diff --git a/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker_policy.go b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker_policy.go
new file mode 100644
index 0000000..463ddc2
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/clientv3/balancer/picker/picker_policy.go
@@ -0,0 +1,49 @@
+// Copyright 2018 The etcd Authors
+//
+// 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.
+
+package picker
+
+import "fmt"
+
+// Policy defines balancer picker policy.
+type Policy uint8
+
+const (
+	// TODO: custom picker is not supported yet.
+	// custom defines custom balancer picker.
+	custom Policy = iota
+
+	// RoundrobinBalanced balance loads over multiple endpoints
+	// and implements failover in roundrobin fashion.
+	RoundrobinBalanced Policy = iota
+
+	// TODO: only send loads to pinned address "RoundrobinFailover"
+	// just like how 3.3 client works
+	//
+	// TODO: priotize leader
+	// TODO: health-check
+	// TODO: weighted roundrobin
+	// TODO: power of two random choice
+)
+
+func (p Policy) String() string {
+	switch p {
+	case custom:
+		panic("'custom' picker policy is not supported yet")
+	case RoundrobinBalanced:
+		return "etcd-client-roundrobin-balanced"
+	default:
+		panic(fmt.Errorf("invalid balancer picker policy (%d)", p))
+	}
+}