diff --git a/vendor/github.com/modern-go/concurrent/.gitignore b/vendor/github.com/modern-go/concurrent/.gitignore
new file mode 100644
index 0000000..3f2bc47
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/.gitignore
@@ -0,0 +1 @@
+/coverage.txt
diff --git a/vendor/github.com/modern-go/concurrent/.travis.yml b/vendor/github.com/modern-go/concurrent/.travis.yml
new file mode 100644
index 0000000..449e67c
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/.travis.yml
@@ -0,0 +1,14 @@
+language: go
+
+go:
+  - 1.8.x
+  - 1.x
+
+before_install:
+  - go get -t -v ./...
+
+script:
+  - ./test.sh
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/github.com/modern-go/concurrent/LICENSE b/vendor/github.com/modern-go/concurrent/LICENSE
new file mode 100644
index 0000000..261eeb9
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
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+
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+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+
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+      transformation or translation of a Source form, including but
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+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
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+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
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+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
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+
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+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
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+
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
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+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/modern-go/concurrent/README.md b/vendor/github.com/modern-go/concurrent/README.md
new file mode 100644
index 0000000..acab320
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/README.md
@@ -0,0 +1,49 @@
+# concurrent
+
+[![Sourcegraph](https://sourcegraph.com/github.com/modern-go/concurrent/-/badge.svg)](https://sourcegraph.com/github.com/modern-go/concurrent?badge)
+[![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/modern-go/concurrent)
+[![Build Status](https://travis-ci.org/modern-go/concurrent.svg?branch=master)](https://travis-ci.org/modern-go/concurrent)
+[![codecov](https://codecov.io/gh/modern-go/concurrent/branch/master/graph/badge.svg)](https://codecov.io/gh/modern-go/concurrent)
+[![rcard](https://goreportcard.com/badge/github.com/modern-go/concurrent)](https://goreportcard.com/report/github.com/modern-go/concurrent)
+[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://raw.githubusercontent.com/modern-go/concurrent/master/LICENSE)
+
+* concurrent.Map: backport sync.Map for go below 1.9
+* concurrent.Executor: goroutine with explicit ownership and cancellable
+
+# concurrent.Map
+
+because sync.Map is only available in go 1.9, we can use concurrent.Map to make code portable
+
+```go
+m := concurrent.NewMap()
+m.Store("hello", "world")
+elem, found := m.Load("hello")
+// elem will be "world"
+// found will be true
+```
+
+# concurrent.Executor
+
+```go
+executor := concurrent.NewUnboundedExecutor()
+executor.Go(func(ctx context.Context) {
+    everyMillisecond := time.NewTicker(time.Millisecond)
+    for {
+        select {
+        case <-ctx.Done():
+            fmt.Println("goroutine exited")
+            return
+        case <-everyMillisecond.C:
+            // do something
+        }
+    }
+})
+time.Sleep(time.Second)
+executor.StopAndWaitForever()
+fmt.Println("executor stopped")
+```
+
+attach goroutine to executor instance, so that we can
+
+* cancel it by stop the executor with Stop/StopAndWait/StopAndWaitForever
+* handle panic by callback: the default behavior will no longer crash your application
\ No newline at end of file
diff --git a/vendor/github.com/modern-go/concurrent/executor.go b/vendor/github.com/modern-go/concurrent/executor.go
new file mode 100644
index 0000000..623dba1
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/executor.go
@@ -0,0 +1,14 @@
+package concurrent
+
+import "context"
+
+// Executor replace go keyword to start a new goroutine
+// the goroutine should cancel itself if the context passed in has been cancelled
+// the goroutine started by the executor, is owned by the executor
+// we can cancel all executors owned by the executor just by stop the executor itself
+// however Executor interface does not Stop method, the one starting and owning executor
+// should use the concrete type of executor, instead of this interface.
+type Executor interface {
+	// Go starts a new goroutine controlled by the context
+	Go(handler func(ctx context.Context))
+}
diff --git a/vendor/github.com/modern-go/concurrent/go_above_19.go b/vendor/github.com/modern-go/concurrent/go_above_19.go
new file mode 100644
index 0000000..aeabf8c
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/go_above_19.go
@@ -0,0 +1,15 @@
+//+build go1.9
+
+package concurrent
+
+import "sync"
+
+// Map is a wrapper for sync.Map introduced in go1.9
+type Map struct {
+	sync.Map
+}
+
+// NewMap creates a thread safe Map
+func NewMap() *Map {
+	return &Map{}
+}
diff --git a/vendor/github.com/modern-go/concurrent/go_below_19.go b/vendor/github.com/modern-go/concurrent/go_below_19.go
new file mode 100644
index 0000000..b9c8df7
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/go_below_19.go
@@ -0,0 +1,33 @@
+//+build !go1.9
+
+package concurrent
+
+import "sync"
+
+// Map implements a thread safe map for go version below 1.9 using mutex
+type Map struct {
+	lock sync.RWMutex
+	data map[interface{}]interface{}
+}
+
+// NewMap creates a thread safe map
+func NewMap() *Map {
+	return &Map{
+		data: make(map[interface{}]interface{}, 32),
+	}
+}
+
+// Load is same as sync.Map Load
+func (m *Map) Load(key interface{}) (elem interface{}, found bool) {
+	m.lock.RLock()
+	elem, found = m.data[key]
+	m.lock.RUnlock()
+	return
+}
+
+// Load is same as sync.Map Store
+func (m *Map) Store(key interface{}, elem interface{}) {
+	m.lock.Lock()
+	m.data[key] = elem
+	m.lock.Unlock()
+}
diff --git a/vendor/github.com/modern-go/concurrent/log.go b/vendor/github.com/modern-go/concurrent/log.go
new file mode 100644
index 0000000..9756fcc
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/log.go
@@ -0,0 +1,13 @@
+package concurrent
+
+import (
+	"os"
+	"log"
+	"io/ioutil"
+)
+
+// ErrorLogger is used to print out error, can be set to writer other than stderr
+var ErrorLogger = log.New(os.Stderr, "", 0)
+
+// InfoLogger is used to print informational message, default to off
+var InfoLogger = log.New(ioutil.Discard, "", 0)
\ No newline at end of file
diff --git a/vendor/github.com/modern-go/concurrent/test.sh b/vendor/github.com/modern-go/concurrent/test.sh
new file mode 100755
index 0000000..d1e6b2e
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/test.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+echo "" > coverage.txt
+
+for d in $(go list ./... | grep -v vendor); do
+    go test -coverprofile=profile.out -coverpkg=github.com/modern-go/concurrent $d
+    if [ -f profile.out ]; then
+        cat profile.out >> coverage.txt
+        rm profile.out
+    fi
+done
diff --git a/vendor/github.com/modern-go/concurrent/unbounded_executor.go b/vendor/github.com/modern-go/concurrent/unbounded_executor.go
new file mode 100644
index 0000000..05a77dc
--- /dev/null
+++ b/vendor/github.com/modern-go/concurrent/unbounded_executor.go
@@ -0,0 +1,119 @@
+package concurrent
+
+import (
+	"context"
+	"fmt"
+	"runtime"
+	"runtime/debug"
+	"sync"
+	"time"
+	"reflect"
+)
+
+// HandlePanic logs goroutine panic by default
+var HandlePanic = func(recovered interface{}, funcName string) {
+	ErrorLogger.Println(fmt.Sprintf("%s panic: %v", funcName, recovered))
+	ErrorLogger.Println(string(debug.Stack()))
+}
+
+// UnboundedExecutor is a executor without limits on counts of alive goroutines
+// it tracks the goroutine started by it, and can cancel them when shutdown
+type UnboundedExecutor struct {
+	ctx                   context.Context
+	cancel                context.CancelFunc
+	activeGoroutinesMutex *sync.Mutex
+	activeGoroutines      map[string]int
+	HandlePanic           func(recovered interface{}, funcName string)
+}
+
+// GlobalUnboundedExecutor has the life cycle of the program itself
+// any goroutine want to be shutdown before main exit can be started from this executor
+// GlobalUnboundedExecutor expects the main function to call stop
+// it does not magically knows the main function exits
+var GlobalUnboundedExecutor = NewUnboundedExecutor()
+
+// NewUnboundedExecutor creates a new UnboundedExecutor,
+// UnboundedExecutor can not be created by &UnboundedExecutor{}
+// HandlePanic can be set with a callback to override global HandlePanic
+func NewUnboundedExecutor() *UnboundedExecutor {
+	ctx, cancel := context.WithCancel(context.TODO())
+	return &UnboundedExecutor{
+		ctx:                   ctx,
+		cancel:                cancel,
+		activeGoroutinesMutex: &sync.Mutex{},
+		activeGoroutines:      map[string]int{},
+	}
+}
+
+// Go starts a new goroutine and tracks its lifecycle.
+// Panic will be recovered and logged automatically, except for StopSignal
+func (executor *UnboundedExecutor) Go(handler func(ctx context.Context)) {
+	pc := reflect.ValueOf(handler).Pointer()
+	f := runtime.FuncForPC(pc)
+	funcName := f.Name()
+	file, line := f.FileLine(pc)
+	executor.activeGoroutinesMutex.Lock()
+	defer executor.activeGoroutinesMutex.Unlock()
+	startFrom := fmt.Sprintf("%s:%d", file, line)
+	executor.activeGoroutines[startFrom] += 1
+	go func() {
+		defer func() {
+			recovered := recover()
+			// if you want to quit a goroutine without trigger HandlePanic
+			// use runtime.Goexit() to quit
+			if recovered != nil {
+				if executor.HandlePanic == nil {
+					HandlePanic(recovered, funcName)
+				} else {
+					executor.HandlePanic(recovered, funcName)
+				}
+			}
+			executor.activeGoroutinesMutex.Lock()
+			executor.activeGoroutines[startFrom] -= 1
+			executor.activeGoroutinesMutex.Unlock()
+		}()
+		handler(executor.ctx)
+	}()
+}
+
+// Stop cancel all goroutines started by this executor without wait
+func (executor *UnboundedExecutor) Stop() {
+	executor.cancel()
+}
+
+// StopAndWaitForever cancel all goroutines started by this executor and
+// wait until all goroutines exited
+func (executor *UnboundedExecutor) StopAndWaitForever() {
+	executor.StopAndWait(context.Background())
+}
+
+// StopAndWait cancel all goroutines started by this executor and wait.
+// Wait can be cancelled by the context passed in.
+func (executor *UnboundedExecutor) StopAndWait(ctx context.Context) {
+	executor.cancel()
+	for {
+		oneHundredMilliseconds := time.NewTimer(time.Millisecond * 100)
+		select {
+		case <-oneHundredMilliseconds.C:
+			if executor.checkNoActiveGoroutines() {
+				return
+			}
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
+func (executor *UnboundedExecutor) checkNoActiveGoroutines() bool {
+	executor.activeGoroutinesMutex.Lock()
+	defer executor.activeGoroutinesMutex.Unlock()
+	for startFrom, count := range executor.activeGoroutines {
+		if count > 0 {
+			InfoLogger.Println("UnboundedExecutor is still waiting goroutines to quit",
+				"startFrom", startFrom,
+				"count", count)
+			return false
+		}
+	}
+	return true
+}
diff --git a/vendor/github.com/modern-go/reflect2/.gitignore b/vendor/github.com/modern-go/reflect2/.gitignore
new file mode 100644
index 0000000..7b26c94
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/.gitignore
@@ -0,0 +1,2 @@
+/vendor
+/coverage.txt
diff --git a/vendor/github.com/modern-go/reflect2/.travis.yml b/vendor/github.com/modern-go/reflect2/.travis.yml
new file mode 100644
index 0000000..fbb4374
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/.travis.yml
@@ -0,0 +1,15 @@
+language: go
+
+go:
+  - 1.8.x
+  - 1.x
+
+before_install:
+  - go get -t -v ./...
+  - go get -t -v github.com/modern-go/reflect2-tests/...
+
+script:
+  - ./test.sh
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/github.com/modern-go/reflect2/Gopkg.lock b/vendor/github.com/modern-go/reflect2/Gopkg.lock
new file mode 100644
index 0000000..2a3a698
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/Gopkg.lock
@@ -0,0 +1,15 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  name = "github.com/modern-go/concurrent"
+  packages = ["."]
+  revision = "e0a39a4cb4216ea8db28e22a69f4ec25610d513a"
+  version = "1.0.0"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "daee8a88b3498b61c5640056665b8b9eea062006f5e596bbb6a3ed9119a11ec7"
+  solver-name = "gps-cdcl"
+  solver-version = 1
diff --git a/vendor/github.com/modern-go/reflect2/Gopkg.toml b/vendor/github.com/modern-go/reflect2/Gopkg.toml
new file mode 100644
index 0000000..2f4f4db
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/Gopkg.toml
@@ -0,0 +1,35 @@
+# Gopkg.toml example
+#
+# Refer to https://golang.github.io/dep/docs/Gopkg.toml.html
+# for detailed Gopkg.toml documentation.
+#
+# required = ["github.com/user/thing/cmd/thing"]
+# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
+#
+# [[constraint]]
+#   name = "github.com/user/project"
+#   version = "1.0.0"
+#
+# [[constraint]]
+#   name = "github.com/user/project2"
+#   branch = "dev"
+#   source = "github.com/myfork/project2"
+#
+# [[override]]
+#   name = "github.com/x/y"
+#   version = "2.4.0"
+#
+# [prune]
+#   non-go = false
+#   go-tests = true
+#   unused-packages = true
+
+ignored = []
+
+[[constraint]]
+  name = "github.com/modern-go/concurrent"
+  version = "1.0.0"
+
+[prune]
+  go-tests = true
+  unused-packages = true
diff --git a/vendor/github.com/modern-go/reflect2/LICENSE b/vendor/github.com/modern-go/reflect2/LICENSE
new file mode 100644
index 0000000..261eeb9
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
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+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
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+      outstanding shares, or (iii) beneficial ownership of such entity.
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+      "You" (or "Your") shall mean an individual or Legal Entity
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+      form, that is based on (or derived from) the Work and for which the
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
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+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
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+
+   7. Disclaimer of Warranty. Unless required by applicable law or
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+
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+
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+
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+
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+
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+
+       http://www.apache.org/licenses/LICENSE-2.0
+
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+   distributed under the License is distributed on an "AS IS" BASIS,
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+   limitations under the License.
diff --git a/vendor/github.com/modern-go/reflect2/README.md b/vendor/github.com/modern-go/reflect2/README.md
new file mode 100644
index 0000000..6f968aa
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/README.md
@@ -0,0 +1,71 @@
+# reflect2
+
+[![Sourcegraph](https://sourcegraph.com/github.com/modern-go/reflect2/-/badge.svg)](https://sourcegraph.com/github.com/modern-go/reflect2?badge)
+[![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/modern-go/reflect2)
+[![Build Status](https://travis-ci.org/modern-go/reflect2.svg?branch=master)](https://travis-ci.org/modern-go/reflect2)
+[![codecov](https://codecov.io/gh/modern-go/reflect2/branch/master/graph/badge.svg)](https://codecov.io/gh/modern-go/reflect2)
+[![rcard](https://goreportcard.com/badge/github.com/modern-go/reflect2)](https://goreportcard.com/report/github.com/modern-go/reflect2)
+[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://raw.githubusercontent.com/modern-go/reflect2/master/LICENSE)
+
+reflect api that avoids runtime reflect.Value cost
+
+* reflect get/set interface{}, with type checking
+* reflect get/set unsafe.Pointer, without type checking
+* `reflect2.TypeByName` works like `Class.forName` found in java
+
+[json-iterator](https://github.com/json-iterator/go) use this package to save runtime dispatching cost.
+This package is designed for low level libraries to optimize reflection performance.
+General application should still use reflect standard library.
+
+# reflect2.TypeByName
+
+```go
+// given package is github.com/your/awesome-package
+type MyStruct struct {
+	// ...
+}
+
+// will return the type
+reflect2.TypeByName("awesome-package.MyStruct")
+// however, if the type has not been used
+// it will be eliminated by compiler, so we can not get it in runtime
+```
+
+# reflect2 get/set interface{}
+
+```go
+valType := reflect2.TypeOf(1)
+i := 1
+j := 10
+valType.Set(&i, &j)
+// i will be 10
+```
+
+to get set `type`, always use its pointer `*type`
+
+# reflect2 get/set unsafe.Pointer
+
+```go
+valType := reflect2.TypeOf(1)
+i := 1
+j := 10
+valType.UnsafeSet(unsafe.Pointer(&i), unsafe.Pointer(&j))
+// i will be 10
+```
+
+to get set `type`, always use its pointer `*type`
+
+# benchmark
+
+Benchmark is not necessary for this package. It does nothing actually.
+As it is just a thin wrapper to make go runtime public. 
+Both `reflect2` and `reflect` call same function 
+provided by `runtime` package exposed by go language.
+
+# unsafe safety
+
+Instead of casting `[]byte` to `sliceHeader` in your application using unsafe.
+We can use reflect2 instead. This way, if `sliceHeader` changes in the future,
+only reflect2 need to be upgraded.
+
+reflect2 tries its best to keep the implementation same as reflect (by testing).
\ No newline at end of file
diff --git a/vendor/github.com/modern-go/reflect2/go_above_17.go b/vendor/github.com/modern-go/reflect2/go_above_17.go
new file mode 100644
index 0000000..5c1cea8
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/go_above_17.go
@@ -0,0 +1,8 @@
+//+build go1.7
+
+package reflect2
+
+import "unsafe"
+
+//go:linkname resolveTypeOff reflect.resolveTypeOff
+func resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer
diff --git a/vendor/github.com/modern-go/reflect2/go_above_19.go b/vendor/github.com/modern-go/reflect2/go_above_19.go
new file mode 100644
index 0000000..c7e3b78
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/go_above_19.go
@@ -0,0 +1,14 @@
+//+build go1.9
+
+package reflect2
+
+import (
+	"unsafe"
+)
+
+//go:linkname makemap reflect.makemap
+func makemap(rtype unsafe.Pointer, cap int) (m unsafe.Pointer)
+
+func makeMapWithSize(rtype unsafe.Pointer, cap int) unsafe.Pointer {
+	return makemap(rtype, cap)
+}
diff --git a/vendor/github.com/modern-go/reflect2/go_below_17.go b/vendor/github.com/modern-go/reflect2/go_below_17.go
new file mode 100644
index 0000000..65a93c8
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/go_below_17.go
@@ -0,0 +1,9 @@
+//+build !go1.7
+
+package reflect2
+
+import "unsafe"
+
+func resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer {
+	return nil
+}
diff --git a/vendor/github.com/modern-go/reflect2/go_below_19.go b/vendor/github.com/modern-go/reflect2/go_below_19.go
new file mode 100644
index 0000000..b050ef7
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/go_below_19.go
@@ -0,0 +1,14 @@
+//+build !go1.9
+
+package reflect2
+
+import (
+	"unsafe"
+)
+
+//go:linkname makemap reflect.makemap
+func makemap(rtype unsafe.Pointer) (m unsafe.Pointer)
+
+func makeMapWithSize(rtype unsafe.Pointer, cap int) unsafe.Pointer {
+	return makemap(rtype)
+}
diff --git a/vendor/github.com/modern-go/reflect2/reflect2.go b/vendor/github.com/modern-go/reflect2/reflect2.go
new file mode 100644
index 0000000..63b49c7
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/reflect2.go
@@ -0,0 +1,298 @@
+package reflect2
+
+import (
+	"github.com/modern-go/concurrent"
+	"reflect"
+	"unsafe"
+)
+
+type Type interface {
+	Kind() reflect.Kind
+	// New return pointer to data of this type
+	New() interface{}
+	// UnsafeNew return the allocated space pointed by unsafe.Pointer
+	UnsafeNew() unsafe.Pointer
+	// PackEFace cast a unsafe pointer to object represented pointer
+	PackEFace(ptr unsafe.Pointer) interface{}
+	// Indirect dereference object represented pointer to this type
+	Indirect(obj interface{}) interface{}
+	// UnsafeIndirect dereference pointer to this type
+	UnsafeIndirect(ptr unsafe.Pointer) interface{}
+	// Type1 returns reflect.Type
+	Type1() reflect.Type
+	Implements(thatType Type) bool
+	String() string
+	RType() uintptr
+	// interface{} of this type has pointer like behavior
+	LikePtr() bool
+	IsNullable() bool
+	IsNil(obj interface{}) bool
+	UnsafeIsNil(ptr unsafe.Pointer) bool
+	Set(obj interface{}, val interface{})
+	UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer)
+	AssignableTo(anotherType Type) bool
+}
+
+type ListType interface {
+	Type
+	Elem() Type
+	SetIndex(obj interface{}, index int, elem interface{})
+	UnsafeSetIndex(obj unsafe.Pointer, index int, elem unsafe.Pointer)
+	GetIndex(obj interface{}, index int) interface{}
+	UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer
+}
+
+type ArrayType interface {
+	ListType
+	Len() int
+}
+
+type SliceType interface {
+	ListType
+	MakeSlice(length int, cap int) interface{}
+	UnsafeMakeSlice(length int, cap int) unsafe.Pointer
+	Grow(obj interface{}, newLength int)
+	UnsafeGrow(ptr unsafe.Pointer, newLength int)
+	Append(obj interface{}, elem interface{})
+	UnsafeAppend(obj unsafe.Pointer, elem unsafe.Pointer)
+	LengthOf(obj interface{}) int
+	UnsafeLengthOf(ptr unsafe.Pointer) int
+	SetNil(obj interface{})
+	UnsafeSetNil(ptr unsafe.Pointer)
+	Cap(obj interface{}) int
+	UnsafeCap(ptr unsafe.Pointer) int
+}
+
+type StructType interface {
+	Type
+	NumField() int
+	Field(i int) StructField
+	FieldByName(name string) StructField
+	FieldByIndex(index []int) StructField
+	FieldByNameFunc(match func(string) bool) StructField
+}
+
+type StructField interface {
+	Offset() uintptr
+	Name() string
+	PkgPath() string
+	Type() Type
+	Tag() reflect.StructTag
+	Index() []int
+	Anonymous() bool
+	Set(obj interface{}, value interface{})
+	UnsafeSet(obj unsafe.Pointer, value unsafe.Pointer)
+	Get(obj interface{}) interface{}
+	UnsafeGet(obj unsafe.Pointer) unsafe.Pointer
+}
+
+type MapType interface {
+	Type
+	Key() Type
+	Elem() Type
+	MakeMap(cap int) interface{}
+	UnsafeMakeMap(cap int) unsafe.Pointer
+	SetIndex(obj interface{}, key interface{}, elem interface{})
+	UnsafeSetIndex(obj unsafe.Pointer, key unsafe.Pointer, elem unsafe.Pointer)
+	TryGetIndex(obj interface{}, key interface{}) (interface{}, bool)
+	GetIndex(obj interface{}, key interface{}) interface{}
+	UnsafeGetIndex(obj unsafe.Pointer, key unsafe.Pointer) unsafe.Pointer
+	Iterate(obj interface{}) MapIterator
+	UnsafeIterate(obj unsafe.Pointer) MapIterator
+}
+
+type MapIterator interface {
+	HasNext() bool
+	Next() (key interface{}, elem interface{})
+	UnsafeNext() (key unsafe.Pointer, elem unsafe.Pointer)
+}
+
+type PtrType interface {
+	Type
+	Elem() Type
+}
+
+type InterfaceType interface {
+	NumMethod() int
+}
+
+type Config struct {
+	UseSafeImplementation bool
+}
+
+type API interface {
+	TypeOf(obj interface{}) Type
+	Type2(type1 reflect.Type) Type
+}
+
+var ConfigUnsafe = Config{UseSafeImplementation: false}.Froze()
+var ConfigSafe = Config{UseSafeImplementation: true}.Froze()
+
+type frozenConfig struct {
+	useSafeImplementation bool
+	cache                 *concurrent.Map
+}
+
+func (cfg Config) Froze() *frozenConfig {
+	return &frozenConfig{
+		useSafeImplementation: cfg.UseSafeImplementation,
+		cache: concurrent.NewMap(),
+	}
+}
+
+func (cfg *frozenConfig) TypeOf(obj interface{}) Type {
+	cacheKey := uintptr(unpackEFace(obj).rtype)
+	typeObj, found := cfg.cache.Load(cacheKey)
+	if found {
+		return typeObj.(Type)
+	}
+	return cfg.Type2(reflect.TypeOf(obj))
+}
+
+func (cfg *frozenConfig) Type2(type1 reflect.Type) Type {
+	if type1 == nil {
+		return nil
+	}
+	cacheKey := uintptr(unpackEFace(type1).data)
+	typeObj, found := cfg.cache.Load(cacheKey)
+	if found {
+		return typeObj.(Type)
+	}
+	type2 := cfg.wrapType(type1)
+	cfg.cache.Store(cacheKey, type2)
+	return type2
+}
+
+func (cfg *frozenConfig) wrapType(type1 reflect.Type) Type {
+	safeType := safeType{Type: type1, cfg: cfg}
+	switch type1.Kind() {
+	case reflect.Struct:
+		if cfg.useSafeImplementation {
+			return &safeStructType{safeType}
+		}
+		return newUnsafeStructType(cfg, type1)
+	case reflect.Array:
+		if cfg.useSafeImplementation {
+			return &safeSliceType{safeType}
+		}
+		return newUnsafeArrayType(cfg, type1)
+	case reflect.Slice:
+		if cfg.useSafeImplementation {
+			return &safeSliceType{safeType}
+		}
+		return newUnsafeSliceType(cfg, type1)
+	case reflect.Map:
+		if cfg.useSafeImplementation {
+			return &safeMapType{safeType}
+		}
+		return newUnsafeMapType(cfg, type1)
+	case reflect.Ptr, reflect.Chan, reflect.Func:
+		if cfg.useSafeImplementation {
+			return &safeMapType{safeType}
+		}
+		return newUnsafePtrType(cfg, type1)
+	case reflect.Interface:
+		if cfg.useSafeImplementation {
+			return &safeMapType{safeType}
+		}
+		if type1.NumMethod() == 0 {
+			return newUnsafeEFaceType(cfg, type1)
+		}
+		return newUnsafeIFaceType(cfg, type1)
+	default:
+		if cfg.useSafeImplementation {
+			return &safeType
+		}
+		return newUnsafeType(cfg, type1)
+	}
+}
+
+func TypeOf(obj interface{}) Type {
+	return ConfigUnsafe.TypeOf(obj)
+}
+
+func TypeOfPtr(obj interface{}) PtrType {
+	return TypeOf(obj).(PtrType)
+}
+
+func Type2(type1 reflect.Type) Type {
+	if type1 == nil {
+		return nil
+	}
+	return ConfigUnsafe.Type2(type1)
+}
+
+func PtrTo(typ Type) Type {
+	return Type2(reflect.PtrTo(typ.Type1()))
+}
+
+func PtrOf(obj interface{}) unsafe.Pointer {
+	return unpackEFace(obj).data
+}
+
+func RTypeOf(obj interface{}) uintptr {
+	return uintptr(unpackEFace(obj).rtype)
+}
+
+func IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	return unpackEFace(obj).data == nil
+}
+
+func IsNullable(kind reflect.Kind) bool {
+	switch kind {
+	case reflect.Ptr, reflect.Map, reflect.Chan, reflect.Func, reflect.Slice, reflect.Interface:
+		return true
+	}
+	return false
+}
+
+func likePtrKind(kind reflect.Kind) bool {
+	switch kind {
+	case reflect.Ptr, reflect.Map, reflect.Chan, reflect.Func:
+		return true
+	}
+	return false
+}
+
+func likePtrType(typ reflect.Type) bool {
+	if likePtrKind(typ.Kind()) {
+		return true
+	}
+	if typ.Kind() == reflect.Struct {
+		if typ.NumField() != 1 {
+			return false
+		}
+		return likePtrType(typ.Field(0).Type)
+	}
+	if typ.Kind() == reflect.Array {
+		if typ.Len() != 1 {
+			return false
+		}
+		return likePtrType(typ.Elem())
+	}
+	return false
+}
+
+// NoEscape hides a pointer from escape analysis.  noescape is
+// the identity function but escape analysis doesn't think the
+// output depends on the input.  noescape is inlined and currently
+// compiles down to zero instructions.
+// USE CAREFULLY!
+//go:nosplit
+func NoEscape(p unsafe.Pointer) unsafe.Pointer {
+	x := uintptr(p)
+	return unsafe.Pointer(x ^ 0)
+}
+
+func UnsafeCastString(str string) []byte {
+	stringHeader := (*reflect.StringHeader)(unsafe.Pointer(&str))
+	sliceHeader := &reflect.SliceHeader{
+		Data: stringHeader.Data,
+		Cap: stringHeader.Len,
+		Len: stringHeader.Len,
+	}
+	return *(*[]byte)(unsafe.Pointer(sliceHeader))
+}
diff --git a/vendor/github.com/modern-go/reflect2/reflect2_amd64.s b/vendor/github.com/modern-go/reflect2/reflect2_amd64.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/reflect2_amd64.s
diff --git a/vendor/github.com/modern-go/reflect2/reflect2_kind.go b/vendor/github.com/modern-go/reflect2/reflect2_kind.go
new file mode 100644
index 0000000..62f299e
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/reflect2_kind.go
@@ -0,0 +1,30 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// DefaultTypeOfKind return the non aliased default type for the kind
+func DefaultTypeOfKind(kind reflect.Kind) Type {
+	return kindTypes[kind]
+}
+
+var kindTypes = map[reflect.Kind]Type{
+	reflect.Bool:          TypeOf(true),
+	reflect.Uint8:         TypeOf(uint8(0)),
+	reflect.Int8:          TypeOf(int8(0)),
+	reflect.Uint16:        TypeOf(uint16(0)),
+	reflect.Int16:         TypeOf(int16(0)),
+	reflect.Uint32:        TypeOf(uint32(0)),
+	reflect.Int32:         TypeOf(int32(0)),
+	reflect.Uint64:        TypeOf(uint64(0)),
+	reflect.Int64:         TypeOf(int64(0)),
+	reflect.Uint:          TypeOf(uint(0)),
+	reflect.Int:           TypeOf(int(0)),
+	reflect.Float32:       TypeOf(float32(0)),
+	reflect.Float64:       TypeOf(float64(0)),
+	reflect.Uintptr:       TypeOf(uintptr(0)),
+	reflect.String:        TypeOf(""),
+	reflect.UnsafePointer: TypeOf(unsafe.Pointer(nil)),
+}
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_386.s b/vendor/github.com/modern-go/reflect2/relfect2_386.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_386.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_amd64p32.s b/vendor/github.com/modern-go/reflect2/relfect2_amd64p32.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_amd64p32.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_arm.s b/vendor/github.com/modern-go/reflect2/relfect2_arm.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_arm.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_arm64.s b/vendor/github.com/modern-go/reflect2/relfect2_arm64.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_arm64.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_mips64x.s b/vendor/github.com/modern-go/reflect2/relfect2_mips64x.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_mips64x.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_mipsx.s b/vendor/github.com/modern-go/reflect2/relfect2_mipsx.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_mipsx.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_ppc64x.s b/vendor/github.com/modern-go/reflect2/relfect2_ppc64x.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_ppc64x.s
diff --git a/vendor/github.com/modern-go/reflect2/relfect2_s390x.s b/vendor/github.com/modern-go/reflect2/relfect2_s390x.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/relfect2_s390x.s
diff --git a/vendor/github.com/modern-go/reflect2/safe_field.go b/vendor/github.com/modern-go/reflect2/safe_field.go
new file mode 100644
index 0000000..d4ba1f4
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/safe_field.go
@@ -0,0 +1,58 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type safeField struct {
+	reflect.StructField
+}
+
+func (field *safeField) Offset() uintptr {
+	return field.StructField.Offset
+}
+
+func (field *safeField) Name() string {
+	return field.StructField.Name
+}
+
+func (field *safeField) PkgPath() string {
+	return field.StructField.PkgPath
+}
+
+func (field *safeField) Type() Type {
+	panic("not implemented")
+}
+
+func (field *safeField) Tag() reflect.StructTag {
+	return field.StructField.Tag
+}
+
+func (field *safeField) Index() []int {
+	return field.StructField.Index
+}
+
+func (field *safeField) Anonymous() bool {
+	return field.StructField.Anonymous
+}
+
+func (field *safeField) Set(obj interface{}, value interface{}) {
+	val := reflect.ValueOf(obj).Elem()
+	val.FieldByIndex(field.Index()).Set(reflect.ValueOf(value).Elem())
+}
+
+func (field *safeField) UnsafeSet(obj unsafe.Pointer, value unsafe.Pointer) {
+	panic("unsafe operation is not supported")
+}
+
+func (field *safeField) Get(obj interface{}) interface{} {
+	val := reflect.ValueOf(obj).Elem().FieldByIndex(field.Index())
+	ptr := reflect.New(val.Type())
+	ptr.Elem().Set(val)
+	return ptr.Interface()
+}
+
+func (field *safeField) UnsafeGet(obj unsafe.Pointer) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
diff --git a/vendor/github.com/modern-go/reflect2/safe_map.go b/vendor/github.com/modern-go/reflect2/safe_map.go
new file mode 100644
index 0000000..8836220
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/safe_map.go
@@ -0,0 +1,101 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type safeMapType struct {
+	safeType
+}
+
+func (type2 *safeMapType) Key() Type {
+	return type2.safeType.cfg.Type2(type2.Type.Key())
+}
+
+func (type2 *safeMapType) MakeMap(cap int) interface{} {
+	ptr := reflect.New(type2.Type)
+	ptr.Elem().Set(reflect.MakeMap(type2.Type))
+	return ptr.Interface()
+}
+
+func (type2 *safeMapType) UnsafeMakeMap(cap int) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeMapType) SetIndex(obj interface{}, key interface{}, elem interface{}) {
+	keyVal := reflect.ValueOf(key)
+	elemVal := reflect.ValueOf(elem)
+	val := reflect.ValueOf(obj)
+	val.Elem().SetMapIndex(keyVal.Elem(), elemVal.Elem())
+}
+
+func (type2 *safeMapType) UnsafeSetIndex(obj unsafe.Pointer, key unsafe.Pointer, elem unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeMapType) TryGetIndex(obj interface{}, key interface{}) (interface{}, bool) {
+	keyVal := reflect.ValueOf(key)
+	if key == nil {
+		keyVal = reflect.New(type2.Type.Key()).Elem()
+	}
+	val := reflect.ValueOf(obj).MapIndex(keyVal)
+	if !val.IsValid() {
+		return nil, false
+	}
+	return val.Interface(), true
+}
+
+func (type2 *safeMapType) GetIndex(obj interface{}, key interface{}) interface{} {
+	val := reflect.ValueOf(obj).Elem()
+	keyVal := reflect.ValueOf(key).Elem()
+	elemVal := val.MapIndex(keyVal)
+	if !elemVal.IsValid() {
+		ptr := reflect.New(reflect.PtrTo(val.Type().Elem()))
+		return ptr.Elem().Interface()
+	}
+	ptr := reflect.New(elemVal.Type())
+	ptr.Elem().Set(elemVal)
+	return ptr.Interface()
+}
+
+func (type2 *safeMapType) UnsafeGetIndex(obj unsafe.Pointer, key unsafe.Pointer) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeMapType) Iterate(obj interface{}) MapIterator {
+	m := reflect.ValueOf(obj).Elem()
+	return &safeMapIterator{
+		m:    m,
+		keys: m.MapKeys(),
+	}
+}
+
+func (type2 *safeMapType) UnsafeIterate(obj unsafe.Pointer) MapIterator {
+	panic("does not support unsafe operation")
+}
+
+type safeMapIterator struct {
+	i    int
+	m    reflect.Value
+	keys []reflect.Value
+}
+
+func (iter *safeMapIterator) HasNext() bool {
+	return iter.i != len(iter.keys)
+}
+
+func (iter *safeMapIterator) Next() (interface{}, interface{}) {
+	key := iter.keys[iter.i]
+	elem := iter.m.MapIndex(key)
+	iter.i += 1
+	keyPtr := reflect.New(key.Type())
+	keyPtr.Elem().Set(key)
+	elemPtr := reflect.New(elem.Type())
+	elemPtr.Elem().Set(elem)
+	return keyPtr.Interface(), elemPtr.Interface()
+}
+
+func (iter *safeMapIterator) UnsafeNext() (unsafe.Pointer, unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
diff --git a/vendor/github.com/modern-go/reflect2/safe_slice.go b/vendor/github.com/modern-go/reflect2/safe_slice.go
new file mode 100644
index 0000000..bcce6fd
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/safe_slice.go
@@ -0,0 +1,92 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type safeSliceType struct {
+	safeType
+}
+
+func (type2 *safeSliceType) SetIndex(obj interface{}, index int, value interface{}) {
+	val := reflect.ValueOf(obj).Elem()
+	elem := reflect.ValueOf(value).Elem()
+	val.Index(index).Set(elem)
+}
+
+func (type2 *safeSliceType) UnsafeSetIndex(obj unsafe.Pointer, index int, value unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) GetIndex(obj interface{}, index int) interface{} {
+	val := reflect.ValueOf(obj).Elem()
+	elem := val.Index(index)
+	ptr := reflect.New(elem.Type())
+	ptr.Elem().Set(elem)
+	return ptr.Interface()
+}
+
+func (type2 *safeSliceType) UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) MakeSlice(length int, cap int) interface{} {
+	val := reflect.MakeSlice(type2.Type, length, cap)
+	ptr := reflect.New(val.Type())
+	ptr.Elem().Set(val)
+	return ptr.Interface()
+}
+
+func (type2 *safeSliceType) UnsafeMakeSlice(length int, cap int) unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) Grow(obj interface{}, newLength int) {
+	oldCap := type2.Cap(obj)
+	oldSlice := reflect.ValueOf(obj).Elem()
+	delta := newLength - oldCap
+	deltaVals := make([]reflect.Value, delta)
+	newSlice := reflect.Append(oldSlice, deltaVals...)
+	oldSlice.Set(newSlice)
+}
+
+func (type2 *safeSliceType) UnsafeGrow(ptr unsafe.Pointer, newLength int) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) Append(obj interface{}, elem interface{}) {
+	val := reflect.ValueOf(obj).Elem()
+	elemVal := reflect.ValueOf(elem).Elem()
+	newVal := reflect.Append(val, elemVal)
+	val.Set(newVal)
+}
+
+func (type2 *safeSliceType) UnsafeAppend(obj unsafe.Pointer, elem unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) SetNil(obj interface{}) {
+	val := reflect.ValueOf(obj).Elem()
+	val.Set(reflect.Zero(val.Type()))
+}
+
+func (type2 *safeSliceType) UnsafeSetNil(ptr unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) LengthOf(obj interface{}) int {
+	return reflect.ValueOf(obj).Elem().Len()
+}
+
+func (type2 *safeSliceType) UnsafeLengthOf(ptr unsafe.Pointer) int {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeSliceType) Cap(obj interface{}) int {
+	return reflect.ValueOf(obj).Elem().Cap()
+}
+
+func (type2 *safeSliceType) UnsafeCap(ptr unsafe.Pointer) int {
+	panic("does not support unsafe operation")
+}
diff --git a/vendor/github.com/modern-go/reflect2/safe_struct.go b/vendor/github.com/modern-go/reflect2/safe_struct.go
new file mode 100644
index 0000000..e5fb9b3
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/safe_struct.go
@@ -0,0 +1,29 @@
+package reflect2
+
+type safeStructType struct {
+	safeType
+}
+
+func (type2 *safeStructType) FieldByName(name string) StructField {
+	field, found := type2.Type.FieldByName(name)
+	if !found {
+		panic("field " + name + " not found")
+	}
+	return &safeField{StructField: field}
+}
+
+func (type2 *safeStructType) Field(i int) StructField {
+	return &safeField{StructField: type2.Type.Field(i)}
+}
+
+func (type2 *safeStructType) FieldByIndex(index []int) StructField {
+	return &safeField{StructField: type2.Type.FieldByIndex(index)}
+}
+
+func (type2 *safeStructType) FieldByNameFunc(match func(string) bool) StructField {
+	field, found := type2.Type.FieldByNameFunc(match)
+	if !found {
+		panic("field match condition not found in " + type2.Type.String())
+	}
+	return &safeField{StructField: field}
+}
diff --git a/vendor/github.com/modern-go/reflect2/safe_type.go b/vendor/github.com/modern-go/reflect2/safe_type.go
new file mode 100644
index 0000000..ee4e7bb
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/safe_type.go
@@ -0,0 +1,78 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type safeType struct {
+	reflect.Type
+	cfg *frozenConfig
+}
+
+func (type2 *safeType) New() interface{} {
+	return reflect.New(type2.Type).Interface()
+}
+
+func (type2 *safeType) UnsafeNew() unsafe.Pointer {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) Elem() Type {
+	return type2.cfg.Type2(type2.Type.Elem())
+}
+
+func (type2 *safeType) Type1() reflect.Type {
+	return type2.Type
+}
+
+func (type2 *safeType) PackEFace(ptr unsafe.Pointer) interface{} {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) Implements(thatType Type) bool {
+	return type2.Type.Implements(thatType.Type1())
+}
+
+func (type2 *safeType) RType() uintptr {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) Indirect(obj interface{}) interface{} {
+	return reflect.Indirect(reflect.ValueOf(obj)).Interface()
+}
+
+func (type2 *safeType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) LikePtr() bool {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) IsNullable() bool {
+	return IsNullable(type2.Kind())
+}
+
+func (type2 *safeType) IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	return reflect.ValueOf(obj).Elem().IsNil()
+}
+
+func (type2 *safeType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) Set(obj interface{}, val interface{}) {
+	reflect.ValueOf(obj).Elem().Set(reflect.ValueOf(val).Elem())
+}
+
+func (type2 *safeType) UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer) {
+	panic("does not support unsafe operation")
+}
+
+func (type2 *safeType) AssignableTo(anotherType Type) bool {
+	return type2.Type1().AssignableTo(anotherType.Type1())
+}
diff --git a/vendor/github.com/modern-go/reflect2/test.sh b/vendor/github.com/modern-go/reflect2/test.sh
new file mode 100755
index 0000000..3d2b976
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/test.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+echo "" > coverage.txt
+
+for d in $(go list github.com/modern-go/reflect2-tests/... | grep -v vendor); do
+    go test -coverprofile=profile.out -coverpkg=github.com/modern-go/reflect2 $d
+    if [ -f profile.out ]; then
+        cat profile.out >> coverage.txt
+        rm profile.out
+    fi
+done
diff --git a/vendor/github.com/modern-go/reflect2/type_map.go b/vendor/github.com/modern-go/reflect2/type_map.go
new file mode 100644
index 0000000..6d48911
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/type_map.go
@@ -0,0 +1,103 @@
+package reflect2
+
+import (
+	"reflect"
+	"runtime"
+	"strings"
+	"unsafe"
+)
+
+// typelinks1 for 1.5 ~ 1.6
+//go:linkname typelinks1 reflect.typelinks
+func typelinks1() [][]unsafe.Pointer
+
+// typelinks2 for 1.7 ~
+//go:linkname typelinks2 reflect.typelinks
+func typelinks2() (sections []unsafe.Pointer, offset [][]int32)
+
+var types = map[string]reflect.Type{}
+var packages = map[string]map[string]reflect.Type{}
+
+func init() {
+	ver := runtime.Version()
+	if ver == "go1.5" || strings.HasPrefix(ver, "go1.5.") {
+		loadGo15Types()
+	} else if ver == "go1.6" || strings.HasPrefix(ver, "go1.6.") {
+		loadGo15Types()
+	} else {
+		loadGo17Types()
+	}
+}
+
+func loadGo15Types() {
+	var obj interface{} = reflect.TypeOf(0)
+	typePtrss := typelinks1()
+	for _, typePtrs := range typePtrss {
+		for _, typePtr := range typePtrs {
+			(*emptyInterface)(unsafe.Pointer(&obj)).word = typePtr
+			typ := obj.(reflect.Type)
+			if typ.Kind() == reflect.Ptr && typ.Elem().Kind() == reflect.Struct {
+				loadedType := typ.Elem()
+				pkgTypes := packages[loadedType.PkgPath()]
+				if pkgTypes == nil {
+					pkgTypes = map[string]reflect.Type{}
+					packages[loadedType.PkgPath()] = pkgTypes
+				}
+				types[loadedType.String()] = loadedType
+				pkgTypes[loadedType.Name()] = loadedType
+			}
+			if typ.Kind() == reflect.Slice && typ.Elem().Kind() == reflect.Ptr &&
+				typ.Elem().Elem().Kind() == reflect.Struct {
+				loadedType := typ.Elem().Elem()
+				pkgTypes := packages[loadedType.PkgPath()]
+				if pkgTypes == nil {
+					pkgTypes = map[string]reflect.Type{}
+					packages[loadedType.PkgPath()] = pkgTypes
+				}
+				types[loadedType.String()] = loadedType
+				pkgTypes[loadedType.Name()] = loadedType
+			}
+		}
+	}
+}
+
+func loadGo17Types() {
+	var obj interface{} = reflect.TypeOf(0)
+	sections, offset := typelinks2()
+	for i, offs := range offset {
+		rodata := sections[i]
+		for _, off := range offs {
+			(*emptyInterface)(unsafe.Pointer(&obj)).word = resolveTypeOff(unsafe.Pointer(rodata), off)
+			typ := obj.(reflect.Type)
+			if typ.Kind() == reflect.Ptr && typ.Elem().Kind() == reflect.Struct {
+				loadedType := typ.Elem()
+				pkgTypes := packages[loadedType.PkgPath()]
+				if pkgTypes == nil {
+					pkgTypes = map[string]reflect.Type{}
+					packages[loadedType.PkgPath()] = pkgTypes
+				}
+				types[loadedType.String()] = loadedType
+				pkgTypes[loadedType.Name()] = loadedType
+			}
+		}
+	}
+}
+
+type emptyInterface struct {
+	typ  unsafe.Pointer
+	word unsafe.Pointer
+}
+
+// TypeByName return the type by its name, just like Class.forName in java
+func TypeByName(typeName string) Type {
+	return Type2(types[typeName])
+}
+
+// TypeByPackageName return the type by its package and name
+func TypeByPackageName(pkgPath string, name string) Type {
+	pkgTypes := packages[pkgPath]
+	if pkgTypes == nil {
+		return nil
+	}
+	return Type2(pkgTypes[name])
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_array.go b/vendor/github.com/modern-go/reflect2/unsafe_array.go
new file mode 100644
index 0000000..76cbdba
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_array.go
@@ -0,0 +1,65 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type UnsafeArrayType struct {
+	unsafeType
+	elemRType  unsafe.Pointer
+	pElemRType unsafe.Pointer
+	elemSize   uintptr
+	likePtr    bool
+}
+
+func newUnsafeArrayType(cfg *frozenConfig, type1 reflect.Type) *UnsafeArrayType {
+	return &UnsafeArrayType{
+		unsafeType: *newUnsafeType(cfg, type1),
+		elemRType:  unpackEFace(type1.Elem()).data,
+		pElemRType: unpackEFace(reflect.PtrTo(type1.Elem())).data,
+		elemSize:   type1.Elem().Size(),
+		likePtr:    likePtrType(type1),
+	}
+}
+
+func (type2 *UnsafeArrayType) LikePtr() bool {
+	return type2.likePtr
+}
+
+func (type2 *UnsafeArrayType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafeArrayType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	if type2.likePtr {
+		return packEFace(type2.rtype, *(*unsafe.Pointer)(ptr))
+	}
+	return packEFace(type2.rtype, ptr)
+}
+
+func (type2 *UnsafeArrayType) SetIndex(obj interface{}, index int, elem interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("ArrayType.SetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	elemEFace := unpackEFace(elem)
+	assertType("ArrayType.SetIndex argument 3", type2.pElemRType, elemEFace.rtype)
+	type2.UnsafeSetIndex(objEFace.data, index, elemEFace.data)
+}
+
+func (type2 *UnsafeArrayType) UnsafeSetIndex(obj unsafe.Pointer, index int, elem unsafe.Pointer) {
+	elemPtr := arrayAt(obj, index, type2.elemSize, "i < s.Len")
+	typedmemmove(type2.elemRType, elemPtr, elem)
+}
+
+func (type2 *UnsafeArrayType) GetIndex(obj interface{}, index int) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("ArrayType.GetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	elemPtr := type2.UnsafeGetIndex(objEFace.data, index)
+	return packEFace(type2.pElemRType, elemPtr)
+}
+
+func (type2 *UnsafeArrayType) UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer {
+	return arrayAt(obj, index, type2.elemSize, "i < s.Len")
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_eface.go b/vendor/github.com/modern-go/reflect2/unsafe_eface.go
new file mode 100644
index 0000000..805010f
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_eface.go
@@ -0,0 +1,59 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type eface struct {
+	rtype unsafe.Pointer
+	data  unsafe.Pointer
+}
+
+func unpackEFace(obj interface{}) *eface {
+	return (*eface)(unsafe.Pointer(&obj))
+}
+
+func packEFace(rtype unsafe.Pointer, data unsafe.Pointer) interface{} {
+	var i interface{}
+	e := (*eface)(unsafe.Pointer(&i))
+	e.rtype = rtype
+	e.data = data
+	return i
+}
+
+type UnsafeEFaceType struct {
+	unsafeType
+}
+
+func newUnsafeEFaceType(cfg *frozenConfig, type1 reflect.Type) *UnsafeEFaceType {
+	return &UnsafeEFaceType{
+		unsafeType: *newUnsafeType(cfg, type1),
+	}
+}
+
+func (type2 *UnsafeEFaceType) IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	objEFace := unpackEFace(obj)
+	assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *UnsafeEFaceType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	if ptr == nil {
+		return true
+	}
+	return unpackEFace(*(*interface{})(ptr)).data == nil
+}
+
+func (type2 *UnsafeEFaceType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafeEFaceType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	return *(*interface{})(ptr)
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_field.go b/vendor/github.com/modern-go/reflect2/unsafe_field.go
new file mode 100644
index 0000000..5eb5313
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_field.go
@@ -0,0 +1,74 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type UnsafeStructField struct {
+	reflect.StructField
+	structType *UnsafeStructType
+	rtype      unsafe.Pointer
+	ptrRType   unsafe.Pointer
+}
+
+func newUnsafeStructField(structType *UnsafeStructType, structField reflect.StructField) *UnsafeStructField {
+	return &UnsafeStructField{
+		StructField: structField,
+		rtype:       unpackEFace(structField.Type).data,
+		ptrRType:    unpackEFace(reflect.PtrTo(structField.Type)).data,
+		structType:  structType,
+	}
+}
+
+func (field *UnsafeStructField) Offset() uintptr {
+	return field.StructField.Offset
+}
+
+func (field *UnsafeStructField) Name() string {
+	return field.StructField.Name
+}
+
+func (field *UnsafeStructField) PkgPath() string {
+	return field.StructField.PkgPath
+}
+
+func (field *UnsafeStructField) Type() Type {
+	return field.structType.cfg.Type2(field.StructField.Type)
+}
+
+func (field *UnsafeStructField) Tag() reflect.StructTag {
+	return field.StructField.Tag
+}
+
+func (field *UnsafeStructField) Index() []int {
+	return field.StructField.Index
+}
+
+func (field *UnsafeStructField) Anonymous() bool {
+	return field.StructField.Anonymous
+}
+
+func (field *UnsafeStructField) Set(obj interface{}, value interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("StructField.SetIndex argument 1", field.structType.ptrRType, objEFace.rtype)
+	valueEFace := unpackEFace(value)
+	assertType("StructField.SetIndex argument 2", field.ptrRType, valueEFace.rtype)
+	field.UnsafeSet(objEFace.data, valueEFace.data)
+}
+
+func (field *UnsafeStructField) UnsafeSet(obj unsafe.Pointer, value unsafe.Pointer) {
+	fieldPtr := add(obj, field.StructField.Offset, "same as non-reflect &v.field")
+	typedmemmove(field.rtype, fieldPtr, value)
+}
+
+func (field *UnsafeStructField) Get(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("StructField.GetIndex argument 1", field.structType.ptrRType, objEFace.rtype)
+	value := field.UnsafeGet(objEFace.data)
+	return packEFace(field.ptrRType, value)
+}
+
+func (field *UnsafeStructField) UnsafeGet(obj unsafe.Pointer) unsafe.Pointer {
+	return add(obj, field.StructField.Offset, "same as non-reflect &v.field")
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_iface.go b/vendor/github.com/modern-go/reflect2/unsafe_iface.go
new file mode 100644
index 0000000..b601955
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_iface.go
@@ -0,0 +1,64 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type iface struct {
+	itab *itab
+	data unsafe.Pointer
+}
+
+type itab struct {
+	ignore unsafe.Pointer
+	rtype  unsafe.Pointer
+}
+
+func IFaceToEFace(ptr unsafe.Pointer) interface{} {
+	iface := (*iface)(ptr)
+	if iface.itab == nil {
+		return nil
+	}
+	return packEFace(iface.itab.rtype, iface.data)
+}
+
+type UnsafeIFaceType struct {
+	unsafeType
+}
+
+func newUnsafeIFaceType(cfg *frozenConfig, type1 reflect.Type) *UnsafeIFaceType {
+	return &UnsafeIFaceType{
+		unsafeType: *newUnsafeType(cfg, type1),
+	}
+}
+
+func (type2 *UnsafeIFaceType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafeIFaceType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	return IFaceToEFace(ptr)
+}
+
+func (type2 *UnsafeIFaceType) IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	objEFace := unpackEFace(obj)
+	assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *UnsafeIFaceType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	if ptr == nil {
+		return true
+	}
+	iface := (*iface)(ptr)
+	if iface.itab == nil {
+		return true
+	}
+	return false
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_link.go b/vendor/github.com/modern-go/reflect2/unsafe_link.go
new file mode 100644
index 0000000..57229c8
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_link.go
@@ -0,0 +1,70 @@
+package reflect2
+
+import "unsafe"
+
+//go:linkname unsafe_New reflect.unsafe_New
+func unsafe_New(rtype unsafe.Pointer) unsafe.Pointer
+
+//go:linkname typedmemmove reflect.typedmemmove
+func typedmemmove(rtype unsafe.Pointer, dst, src unsafe.Pointer)
+
+//go:linkname unsafe_NewArray reflect.unsafe_NewArray
+func unsafe_NewArray(rtype unsafe.Pointer, length int) unsafe.Pointer
+
+// typedslicecopy copies a slice of elemType values from src to dst,
+// returning the number of elements copied.
+//go:linkname typedslicecopy reflect.typedslicecopy
+//go:noescape
+func typedslicecopy(elemType unsafe.Pointer, dst, src sliceHeader) int
+
+//go:linkname mapassign reflect.mapassign
+//go:noescape
+func mapassign(rtype unsafe.Pointer, m unsafe.Pointer, key, val unsafe.Pointer)
+
+//go:linkname mapaccess reflect.mapaccess
+//go:noescape
+func mapaccess(rtype unsafe.Pointer, m unsafe.Pointer, key unsafe.Pointer) (val unsafe.Pointer)
+
+// m escapes into the return value, but the caller of mapiterinit
+// doesn't let the return value escape.
+//go:noescape
+//go:linkname mapiterinit reflect.mapiterinit
+func mapiterinit(rtype unsafe.Pointer, m unsafe.Pointer) *hiter
+
+//go:noescape
+//go:linkname mapiternext reflect.mapiternext
+func mapiternext(it *hiter)
+
+//go:linkname ifaceE2I reflect.ifaceE2I
+func ifaceE2I(rtype unsafe.Pointer, src interface{}, dst unsafe.Pointer)
+
+// A hash iteration structure.
+// If you modify hiter, also change cmd/internal/gc/reflect.go to indicate
+// the layout of this structure.
+type hiter struct {
+	key   unsafe.Pointer // Must be in first position.  Write nil to indicate iteration end (see cmd/internal/gc/range.go).
+	value unsafe.Pointer // Must be in second position (see cmd/internal/gc/range.go).
+	// rest fields are ignored
+}
+
+// add returns p+x.
+//
+// The whySafe string is ignored, so that the function still inlines
+// as efficiently as p+x, but all call sites should use the string to
+// record why the addition is safe, which is to say why the addition
+// does not cause x to advance to the very end of p's allocation
+// and therefore point incorrectly at the next block in memory.
+func add(p unsafe.Pointer, x uintptr, whySafe string) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(p) + x)
+}
+
+// arrayAt returns the i-th element of p,
+// an array whose elements are eltSize bytes wide.
+// The array pointed at by p must have at least i+1 elements:
+// it is invalid (but impossible to check here) to pass i >= len,
+// because then the result will point outside the array.
+// whySafe must explain why i < len. (Passing "i < len" is fine;
+// the benefit is to surface this assumption at the call site.)
+func arrayAt(p unsafe.Pointer, i int, eltSize uintptr, whySafe string) unsafe.Pointer {
+	return add(p, uintptr(i)*eltSize, "i < len")
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_map.go b/vendor/github.com/modern-go/reflect2/unsafe_map.go
new file mode 100644
index 0000000..f2e76e6
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_map.go
@@ -0,0 +1,138 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type UnsafeMapType struct {
+	unsafeType
+	pKeyRType  unsafe.Pointer
+	pElemRType unsafe.Pointer
+}
+
+func newUnsafeMapType(cfg *frozenConfig, type1 reflect.Type) MapType {
+	return &UnsafeMapType{
+		unsafeType: *newUnsafeType(cfg, type1),
+		pKeyRType:  unpackEFace(reflect.PtrTo(type1.Key())).data,
+		pElemRType: unpackEFace(reflect.PtrTo(type1.Elem())).data,
+	}
+}
+
+func (type2 *UnsafeMapType) IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	objEFace := unpackEFace(obj)
+	assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *UnsafeMapType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	if ptr == nil {
+		return true
+	}
+	return *(*unsafe.Pointer)(ptr) == nil
+}
+
+func (type2 *UnsafeMapType) LikePtr() bool {
+	return true
+}
+
+func (type2 *UnsafeMapType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("MapType.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafeMapType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	return packEFace(type2.rtype, *(*unsafe.Pointer)(ptr))
+}
+
+func (type2 *UnsafeMapType) Key() Type {
+	return type2.cfg.Type2(type2.Type.Key())
+}
+
+func (type2 *UnsafeMapType) MakeMap(cap int) interface{} {
+	return packEFace(type2.ptrRType, type2.UnsafeMakeMap(cap))
+}
+
+func (type2 *UnsafeMapType) UnsafeMakeMap(cap int) unsafe.Pointer {
+	m := makeMapWithSize(type2.rtype, cap)
+	return unsafe.Pointer(&m)
+}
+
+func (type2 *UnsafeMapType) SetIndex(obj interface{}, key interface{}, elem interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("MapType.SetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	keyEFace := unpackEFace(key)
+	assertType("MapType.SetIndex argument 2", type2.pKeyRType, keyEFace.rtype)
+	elemEFace := unpackEFace(elem)
+	assertType("MapType.SetIndex argument 3", type2.pElemRType, elemEFace.rtype)
+	type2.UnsafeSetIndex(objEFace.data, keyEFace.data, elemEFace.data)
+}
+
+func (type2 *UnsafeMapType) UnsafeSetIndex(obj unsafe.Pointer, key unsafe.Pointer, elem unsafe.Pointer) {
+	mapassign(type2.rtype, *(*unsafe.Pointer)(obj), key, elem)
+}
+
+func (type2 *UnsafeMapType) TryGetIndex(obj interface{}, key interface{}) (interface{}, bool) {
+	objEFace := unpackEFace(obj)
+	assertType("MapType.TryGetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	keyEFace := unpackEFace(key)
+	assertType("MapType.TryGetIndex argument 2", type2.pKeyRType, keyEFace.rtype)
+	elemPtr := type2.UnsafeGetIndex(objEFace.data, keyEFace.data)
+	if elemPtr == nil {
+		return nil, false
+	}
+	return packEFace(type2.pElemRType, elemPtr), true
+}
+
+func (type2 *UnsafeMapType) GetIndex(obj interface{}, key interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("MapType.GetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	keyEFace := unpackEFace(key)
+	assertType("MapType.GetIndex argument 2", type2.pKeyRType, keyEFace.rtype)
+	elemPtr := type2.UnsafeGetIndex(objEFace.data, keyEFace.data)
+	return packEFace(type2.pElemRType, elemPtr)
+}
+
+func (type2 *UnsafeMapType) UnsafeGetIndex(obj unsafe.Pointer, key unsafe.Pointer) unsafe.Pointer {
+	return mapaccess(type2.rtype, *(*unsafe.Pointer)(obj), key)
+}
+
+func (type2 *UnsafeMapType) Iterate(obj interface{}) MapIterator {
+	objEFace := unpackEFace(obj)
+	assertType("MapType.Iterate argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIterate(objEFace.data)
+}
+
+func (type2 *UnsafeMapType) UnsafeIterate(obj unsafe.Pointer) MapIterator {
+	return &UnsafeMapIterator{
+		hiter:      mapiterinit(type2.rtype, *(*unsafe.Pointer)(obj)),
+		pKeyRType:  type2.pKeyRType,
+		pElemRType: type2.pElemRType,
+	}
+}
+
+type UnsafeMapIterator struct {
+	*hiter
+	pKeyRType  unsafe.Pointer
+	pElemRType unsafe.Pointer
+}
+
+func (iter *UnsafeMapIterator) HasNext() bool {
+	return iter.key != nil
+}
+
+func (iter *UnsafeMapIterator) Next() (interface{}, interface{}) {
+	key, elem := iter.UnsafeNext()
+	return packEFace(iter.pKeyRType, key), packEFace(iter.pElemRType, elem)
+}
+
+func (iter *UnsafeMapIterator) UnsafeNext() (unsafe.Pointer, unsafe.Pointer) {
+	key := iter.key
+	elem := iter.value
+	mapiternext(iter.hiter)
+	return key, elem
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_ptr.go b/vendor/github.com/modern-go/reflect2/unsafe_ptr.go
new file mode 100644
index 0000000..8e5ec9c
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_ptr.go
@@ -0,0 +1,46 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type UnsafePtrType struct {
+	unsafeType
+}
+
+func newUnsafePtrType(cfg *frozenConfig, type1 reflect.Type) *UnsafePtrType {
+	return &UnsafePtrType{
+		unsafeType: *newUnsafeType(cfg, type1),
+	}
+}
+
+func (type2 *UnsafePtrType) IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	objEFace := unpackEFace(obj)
+	assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *UnsafePtrType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	if ptr == nil {
+		return true
+	}
+	return *(*unsafe.Pointer)(ptr) == nil
+}
+
+func (type2 *UnsafePtrType) LikePtr() bool {
+	return true
+}
+
+func (type2 *UnsafePtrType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafePtrType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	return packEFace(type2.rtype, *(*unsafe.Pointer)(ptr))
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_slice.go b/vendor/github.com/modern-go/reflect2/unsafe_slice.go
new file mode 100644
index 0000000..1c6d876
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_slice.go
@@ -0,0 +1,177 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// sliceHeader is a safe version of SliceHeader used within this package.
+type sliceHeader struct {
+	Data unsafe.Pointer
+	Len  int
+	Cap  int
+}
+
+type UnsafeSliceType struct {
+	unsafeType
+	elemRType  unsafe.Pointer
+	pElemRType unsafe.Pointer
+	elemSize   uintptr
+}
+
+func newUnsafeSliceType(cfg *frozenConfig, type1 reflect.Type) SliceType {
+	elemType := type1.Elem()
+	return &UnsafeSliceType{
+		unsafeType: *newUnsafeType(cfg, type1),
+		pElemRType: unpackEFace(reflect.PtrTo(elemType)).data,
+		elemRType:  unpackEFace(elemType).data,
+		elemSize:   elemType.Size(),
+	}
+}
+
+func (type2 *UnsafeSliceType) Set(obj interface{}, val interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Set argument 1", type2.ptrRType, objEFace.rtype)
+	valEFace := unpackEFace(val)
+	assertType("Type.Set argument 2", type2.ptrRType, valEFace.rtype)
+	type2.UnsafeSet(objEFace.data, valEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer) {
+	*(*sliceHeader)(ptr) = *(*sliceHeader)(val)
+}
+
+func (type2 *UnsafeSliceType) IsNil(obj interface{}) bool {
+	if obj == nil {
+		return true
+	}
+	objEFace := unpackEFace(obj)
+	assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	if ptr == nil {
+		return true
+	}
+	return (*sliceHeader)(ptr).Data == nil
+}
+
+func (type2 *UnsafeSliceType) SetNil(obj interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.SetNil argument 1", type2.ptrRType, objEFace.rtype)
+	type2.UnsafeSetNil(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeSetNil(ptr unsafe.Pointer) {
+	header := (*sliceHeader)(ptr)
+	header.Len = 0
+	header.Cap = 0
+	header.Data = nil
+}
+
+func (type2 *UnsafeSliceType) MakeSlice(length int, cap int) interface{} {
+	return packEFace(type2.ptrRType, type2.UnsafeMakeSlice(length, cap))
+}
+
+func (type2 *UnsafeSliceType) UnsafeMakeSlice(length int, cap int) unsafe.Pointer {
+	header := &sliceHeader{unsafe_NewArray(type2.elemRType, cap), length, cap}
+	return unsafe.Pointer(header)
+}
+
+func (type2 *UnsafeSliceType) LengthOf(obj interface{}) int {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.Len argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeLengthOf(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeLengthOf(obj unsafe.Pointer) int {
+	header := (*sliceHeader)(obj)
+	return header.Len
+}
+
+func (type2 *UnsafeSliceType) SetIndex(obj interface{}, index int, elem interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.SetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	elemEFace := unpackEFace(elem)
+	assertType("SliceType.SetIndex argument 3", type2.pElemRType, elemEFace.rtype)
+	type2.UnsafeSetIndex(objEFace.data, index, elemEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeSetIndex(obj unsafe.Pointer, index int, elem unsafe.Pointer) {
+	header := (*sliceHeader)(obj)
+	elemPtr := arrayAt(header.Data, index, type2.elemSize, "i < s.Len")
+	typedmemmove(type2.elemRType, elemPtr, elem)
+}
+
+func (type2 *UnsafeSliceType) GetIndex(obj interface{}, index int) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.GetIndex argument 1", type2.ptrRType, objEFace.rtype)
+	elemPtr := type2.UnsafeGetIndex(objEFace.data, index)
+	return packEFace(type2.pElemRType, elemPtr)
+}
+
+func (type2 *UnsafeSliceType) UnsafeGetIndex(obj unsafe.Pointer, index int) unsafe.Pointer {
+	header := (*sliceHeader)(obj)
+	return arrayAt(header.Data, index, type2.elemSize, "i < s.Len")
+}
+
+func (type2 *UnsafeSliceType) Append(obj interface{}, elem interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.Append argument 1", type2.ptrRType, objEFace.rtype)
+	elemEFace := unpackEFace(elem)
+	assertType("SliceType.Append argument 2", type2.pElemRType, elemEFace.rtype)
+	type2.UnsafeAppend(objEFace.data, elemEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeAppend(obj unsafe.Pointer, elem unsafe.Pointer) {
+	header := (*sliceHeader)(obj)
+	oldLen := header.Len
+	type2.UnsafeGrow(obj, oldLen+1)
+	type2.UnsafeSetIndex(obj, oldLen, elem)
+}
+
+func (type2 *UnsafeSliceType) Cap(obj interface{}) int {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.Cap argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeCap(objEFace.data)
+}
+
+func (type2 *UnsafeSliceType) UnsafeCap(ptr unsafe.Pointer) int {
+	return (*sliceHeader)(ptr).Cap
+}
+
+func (type2 *UnsafeSliceType) Grow(obj interface{}, newLength int) {
+	objEFace := unpackEFace(obj)
+	assertType("SliceType.Grow argument 1", type2.ptrRType, objEFace.rtype)
+	type2.UnsafeGrow(objEFace.data, newLength)
+}
+
+func (type2 *UnsafeSliceType) UnsafeGrow(obj unsafe.Pointer, newLength int) {
+	header := (*sliceHeader)(obj)
+	if newLength <= header.Cap {
+		header.Len = newLength
+		return
+	}
+	newCap := calcNewCap(header.Cap, newLength)
+	newHeader := (*sliceHeader)(type2.UnsafeMakeSlice(header.Len, newCap))
+	typedslicecopy(type2.elemRType, *newHeader, *header)
+	header.Data = newHeader.Data
+	header.Cap = newHeader.Cap
+	header.Len = newLength
+}
+
+func calcNewCap(cap int, expectedCap int) int {
+	if cap == 0 {
+		cap = expectedCap
+	} else {
+		for cap < expectedCap {
+			if cap < 1024 {
+				cap += cap
+			} else {
+				cap += cap / 4
+			}
+		}
+	}
+	return cap
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_struct.go b/vendor/github.com/modern-go/reflect2/unsafe_struct.go
new file mode 100644
index 0000000..804d916
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_struct.go
@@ -0,0 +1,59 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type UnsafeStructType struct {
+	unsafeType
+	likePtr bool
+}
+
+func newUnsafeStructType(cfg *frozenConfig, type1 reflect.Type) *UnsafeStructType {
+	return &UnsafeStructType{
+		unsafeType: *newUnsafeType(cfg, type1),
+		likePtr:    likePtrType(type1),
+	}
+}
+
+func (type2 *UnsafeStructType) LikePtr() bool {
+	return type2.likePtr
+}
+
+func (type2 *UnsafeStructType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *UnsafeStructType) UnsafeIndirect(ptr unsafe.Pointer) interface{} {
+	if type2.likePtr {
+		return packEFace(type2.rtype, *(*unsafe.Pointer)(ptr))
+	}
+	return packEFace(type2.rtype, ptr)
+}
+
+func (type2 *UnsafeStructType) FieldByName(name string) StructField {
+	structField, found := type2.Type.FieldByName(name)
+	if !found {
+		return nil
+	}
+	return newUnsafeStructField(type2, structField)
+}
+
+func (type2 *UnsafeStructType) Field(i int) StructField {
+	return newUnsafeStructField(type2, type2.Type.Field(i))
+}
+
+func (type2 *UnsafeStructType) FieldByIndex(index []int) StructField {
+	return newUnsafeStructField(type2, type2.Type.FieldByIndex(index))
+}
+
+func (type2 *UnsafeStructType) FieldByNameFunc(match func(string) bool) StructField {
+	structField, found := type2.Type.FieldByNameFunc(match)
+	if !found {
+		panic("field match condition not found in " + type2.Type.String())
+	}
+	return newUnsafeStructField(type2, structField)
+}
diff --git a/vendor/github.com/modern-go/reflect2/unsafe_type.go b/vendor/github.com/modern-go/reflect2/unsafe_type.go
new file mode 100644
index 0000000..1394171
--- /dev/null
+++ b/vendor/github.com/modern-go/reflect2/unsafe_type.go
@@ -0,0 +1,85 @@
+package reflect2
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+type unsafeType struct {
+	safeType
+	rtype    unsafe.Pointer
+	ptrRType unsafe.Pointer
+}
+
+func newUnsafeType(cfg *frozenConfig, type1 reflect.Type) *unsafeType {
+	return &unsafeType{
+		safeType: safeType{
+			Type: type1,
+			cfg:  cfg,
+		},
+		rtype:    unpackEFace(type1).data,
+		ptrRType: unpackEFace(reflect.PtrTo(type1)).data,
+	}
+}
+
+func (type2 *unsafeType) Set(obj interface{}, val interface{}) {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Set argument 1", type2.ptrRType, objEFace.rtype)
+	valEFace := unpackEFace(val)
+	assertType("Type.Set argument 2", type2.ptrRType, valEFace.rtype)
+	type2.UnsafeSet(objEFace.data, valEFace.data)
+}
+
+func (type2 *unsafeType) UnsafeSet(ptr unsafe.Pointer, val unsafe.Pointer) {
+	typedmemmove(type2.rtype, ptr, val)
+}
+
+func (type2 *unsafeType) IsNil(obj interface{}) bool {
+	objEFace := unpackEFace(obj)
+	assertType("Type.IsNil argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIsNil(objEFace.data)
+}
+
+func (type2 *unsafeType) UnsafeIsNil(ptr unsafe.Pointer) bool {
+	return ptr == nil
+}
+
+func (type2 *unsafeType) UnsafeNew() unsafe.Pointer {
+	return unsafe_New(type2.rtype)
+}
+
+func (type2 *unsafeType) New() interface{} {
+	return packEFace(type2.ptrRType, type2.UnsafeNew())
+}
+
+func (type2 *unsafeType) PackEFace(ptr unsafe.Pointer) interface{} {
+	return packEFace(type2.ptrRType, ptr)
+}
+
+func (type2 *unsafeType) RType() uintptr {
+	return uintptr(type2.rtype)
+}
+
+func (type2 *unsafeType) Indirect(obj interface{}) interface{} {
+	objEFace := unpackEFace(obj)
+	assertType("Type.Indirect argument 1", type2.ptrRType, objEFace.rtype)
+	return type2.UnsafeIndirect(objEFace.data)
+}
+
+func (type2 *unsafeType) UnsafeIndirect(obj unsafe.Pointer) interface{} {
+	return packEFace(type2.rtype, obj)
+}
+
+func (type2 *unsafeType) LikePtr() bool {
+	return false
+}
+
+func assertType(where string, expectRType unsafe.Pointer, actualRType unsafe.Pointer) {
+	if expectRType != actualRType {
+		expectType := reflect.TypeOf(0)
+		(*iface)(unsafe.Pointer(&expectType)).data = expectRType
+		actualType := reflect.TypeOf(0)
+		(*iface)(unsafe.Pointer(&actualType)).data = actualRType
+		panic(where + ": expect " + expectType.String() + ", actual " + actualType.String())
+	}
+}