$options * * @return BidiStream */ public function startBidiStreamingCall(Call $call, array $options); /** * Starts a client streaming call. * * @param Call $call * @param array $options * * @return ClientStream */ public function startClientStreamingCall(Call $call, array $options); /** * Starts a server streaming call. * * @param Call $call * @param array $options * * @return ServerStream */ public function startServerStreamingCall(Call $call, array $options); /** * Returns a promise used to execute network requests. * * @param Call $call * @param array $options * * @return PromiseInterface * @throws ValidationException */ public function startUnaryCall(Call $call, array $options); /** * Closes the connection, if one exists. * * @return void */ public function close(); }