diff --git a/vendor/google.golang.org/grpc/call.go b/vendor/google.golang.org/grpc/call.go
new file mode 100644
index 0000000..100f05d
--- /dev/null
+++ b/vendor/google.golang.org/grpc/call.go
@@ -0,0 +1,74 @@
+/*
+ *
+ * Copyright 2014 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 grpc
+
+import (
+	"context"
+)
+
+// Invoke sends the RPC request on the wire and returns after response is
+// received.  This is typically called by generated code.
+//
+// All errors returned by Invoke are compatible with the status package.
+func (cc *ClientConn) Invoke(ctx context.Context, method string, args, reply interface{}, opts ...CallOption) error {
+	// allow interceptor to see all applicable call options, which means those
+	// configured as defaults from dial option as well as per-call options
+	opts = combine(cc.dopts.callOptions, opts)
+
+	if cc.dopts.unaryInt != nil {
+		return cc.dopts.unaryInt(ctx, method, args, reply, cc, invoke, opts...)
+	}
+	return invoke(ctx, method, args, reply, cc, opts...)
+}
+
+func combine(o1 []CallOption, o2 []CallOption) []CallOption {
+	// we don't use append because o1 could have extra capacity whose
+	// elements would be overwritten, which could cause inadvertent
+	// sharing (and race connditions) between concurrent calls
+	if len(o1) == 0 {
+		return o2
+	} else if len(o2) == 0 {
+		return o1
+	}
+	ret := make([]CallOption, len(o1)+len(o2))
+	copy(ret, o1)
+	copy(ret[len(o1):], o2)
+	return ret
+}
+
+// Invoke sends the RPC request on the wire and returns after response is
+// received.  This is typically called by generated code.
+//
+// DEPRECATED: Use ClientConn.Invoke instead.
+func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
+	return cc.Invoke(ctx, method, args, reply, opts...)
+}
+
+var unaryStreamDesc = &StreamDesc{ServerStreams: false, ClientStreams: false}
+
+func invoke(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, opts ...CallOption) error {
+	cs, err := newClientStream(ctx, unaryStreamDesc, cc, method, opts...)
+	if err != nil {
+		return err
+	}
+	if err := cs.SendMsg(req); err != nil {
+		return err
+	}
+	return cs.RecvMsg(reply)
+}