diff --git a/go/vendor/google.golang.org/grpc/stats/handlers.go b/go/vendor/google.golang.org/grpc/stats/handlers.go
new file mode 100644
index 0000000..05b384c
--- /dev/null
+++ b/go/vendor/google.golang.org/grpc/stats/handlers.go
@@ -0,0 +1,64 @@
+/*
+ *
+ * Copyright 2016 gRPC 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 stats
+
+import (
+	"net"
+
+	"golang.org/x/net/context"
+)
+
+// ConnTagInfo defines the relevant information needed by connection context tagger.
+type ConnTagInfo struct {
+	// RemoteAddr is the remote address of the corresponding connection.
+	RemoteAddr net.Addr
+	// LocalAddr is the local address of the corresponding connection.
+	LocalAddr net.Addr
+}
+
+// RPCTagInfo defines the relevant information needed by RPC context tagger.
+type RPCTagInfo struct {
+	// FullMethodName is the RPC method in the format of /package.service/method.
+	FullMethodName string
+	// FailFast indicates if this RPC is failfast.
+	// This field is only valid on client side, it's always false on server side.
+	FailFast bool
+}
+
+// Handler defines the interface for the related stats handling (e.g., RPCs, connections).
+type Handler interface {
+	// TagRPC can attach some information to the given context.
+	// The context used for the rest lifetime of the RPC will be derived from
+	// the returned context.
+	TagRPC(context.Context, *RPCTagInfo) context.Context
+	// HandleRPC processes the RPC stats.
+	HandleRPC(context.Context, RPCStats)
+
+	// TagConn can attach some information to the given context.
+	// The returned context will be used for stats handling.
+	// For conn stats handling, the context used in HandleConn for this
+	// connection will be derived from the context returned.
+	// For RPC stats handling,
+	//  - On server side, the context used in HandleRPC for all RPCs on this
+	// connection will be derived from the context returned.
+	//  - On client side, the context is not derived from the context returned.
+	TagConn(context.Context, *ConnTagInfo) context.Context
+	// HandleConn processes the Conn stats.
+	HandleConn(context.Context, ConnStats)
+}