code: function handleBidiStreaming(call, handler, metadata) {
    var stream = new ServerDuplexStream(call, metadata, handler.serialize,
                                        handler.deserialize);
    stream.waitForCancel();
    handler.func(stream);
  }
docs: User provided method to handle bidirectional streaming calls on the server.
  @callback grpc.Server~handleBidiStreamingCall
  @param {grpc~ServerDuplexStream} call The call object
   
  Fully handle a bidirectional streaming call
  @private
  @param {grpc.internal~Call} call The call to handle
  @param {Object} handler Request handler object for the method that was called
  @param {grpc~Server.handleBidiStreamingCall} handler.func The handler
  function
  @param {grpc~deserialize} handler.deserialize The deserialization function
  for request data
  @param {grpc~serialize} handler.serialize The serialization function for
  response data
  @param {Metadata} metadata Metadata from the client