diff --git a/vendor/google.golang.org/protobuf/runtime/protoiface/methods.go b/vendor/google.golang.org/protobuf/runtime/protoiface/methods.go
new file mode 100644
index 0000000..32c04f6
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/runtime/protoiface/methods.go
@@ -0,0 +1,167 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package protoiface contains types referenced or implemented by messages.
+//
+// WARNING: This package should only be imported by message implementations.
+// The functionality found in this package should be accessed through
+// higher-level abstractions provided by the proto package.
+package protoiface
+
+import (
+	"google.golang.org/protobuf/internal/pragma"
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+// Methods is a set of optional fast-path implementations of various operations.
+type Methods = struct {
+	pragma.NoUnkeyedLiterals
+
+	// Flags indicate support for optional features.
+	Flags SupportFlags
+
+	// Size returns the size in bytes of the wire-format encoding of a message.
+	// Marshal must be provided if a custom Size is provided.
+	Size func(SizeInput) SizeOutput
+
+	// Marshal formats a message in the wire-format encoding to the provided buffer.
+	// Size should be provided if a custom Marshal is provided.
+	// It must not return an error for a partial message.
+	Marshal func(MarshalInput) (MarshalOutput, error)
+
+	// Unmarshal parses the wire-format encoding and merges the result into a message.
+	// It must not reset the target message or return an error for a partial message.
+	Unmarshal func(UnmarshalInput) (UnmarshalOutput, error)
+
+	// Merge merges the contents of a source message into a destination message.
+	Merge func(MergeInput) MergeOutput
+
+	// CheckInitialized returns an error if any required fields in the message are not set.
+	CheckInitialized func(CheckInitializedInput) (CheckInitializedOutput, error)
+}
+
+// SupportFlags indicate support for optional features.
+type SupportFlags = uint64
+
+const (
+	// SupportMarshalDeterministic reports whether MarshalOptions.Deterministic is supported.
+	SupportMarshalDeterministic SupportFlags = 1 << iota
+
+	// SupportUnmarshalDiscardUnknown reports whether UnmarshalOptions.DiscardUnknown is supported.
+	SupportUnmarshalDiscardUnknown
+)
+
+// SizeInput is input to the Size method.
+type SizeInput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Message protoreflect.Message
+	Flags   MarshalInputFlags
+}
+
+// SizeOutput is output from the Size method.
+type SizeOutput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Size int
+}
+
+// MarshalInput is input to the Marshal method.
+type MarshalInput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Message protoreflect.Message
+	Buf     []byte // output is appended to this buffer
+	Flags   MarshalInputFlags
+}
+
+// MarshalOutput is output from the Marshal method.
+type MarshalOutput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Buf []byte // contains marshaled message
+}
+
+// MarshalInputFlags configure the marshaler.
+// Most flags correspond to fields in proto.MarshalOptions.
+type MarshalInputFlags = uint8
+
+const (
+	MarshalDeterministic MarshalInputFlags = 1 << iota
+	MarshalUseCachedSize
+)
+
+// UnmarshalInput is input to the Unmarshal method.
+type UnmarshalInput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Message  protoreflect.Message
+	Buf      []byte // input buffer
+	Flags    UnmarshalInputFlags
+	Resolver interface {
+		FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error)
+		FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error)
+	}
+}
+
+// UnmarshalOutput is output from the Unmarshal method.
+type UnmarshalOutput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Flags UnmarshalOutputFlags
+}
+
+// UnmarshalInputFlags configure the unmarshaler.
+// Most flags correspond to fields in proto.UnmarshalOptions.
+type UnmarshalInputFlags = uint8
+
+const (
+	UnmarshalDiscardUnknown UnmarshalInputFlags = 1 << iota
+)
+
+// UnmarshalOutputFlags are output from the Unmarshal method.
+type UnmarshalOutputFlags = uint8
+
+const (
+	// UnmarshalInitialized may be set on return if all required fields are known to be set.
+	// If unset, then it does not necessarily indicate that the message is uninitialized,
+	// only that its status could not be confirmed.
+	UnmarshalInitialized UnmarshalOutputFlags = 1 << iota
+)
+
+// MergeInput is input to the Merge method.
+type MergeInput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Source      protoreflect.Message
+	Destination protoreflect.Message
+}
+
+// MergeOutput is output from the Merge method.
+type MergeOutput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Flags MergeOutputFlags
+}
+
+// MergeOutputFlags are output from the Merge method.
+type MergeOutputFlags = uint8
+
+const (
+	// MergeComplete reports whether the merge was performed.
+	// If unset, the merger must have made no changes to the destination.
+	MergeComplete MergeOutputFlags = 1 << iota
+)
+
+// CheckInitializedInput is input to the CheckInitialized method.
+type CheckInitializedInput = struct {
+	pragma.NoUnkeyedLiterals
+
+	Message protoreflect.Message
+}
+
+// CheckInitializedOutput is output from the CheckInitialized method.
+type CheckInitializedOutput = struct {
+	pragma.NoUnkeyedLiterals
+}