/**
  * Create a new simple (single request/single response) active call.
  * @param Channel $channel The channel to communicate on
  * @param string $method The method to call on the remote server
  * @param callable $deserialize The function to deserialize a value
  * @param Traversable $arg_iter The iterator of arguments to send
  * @param array $metadata Metadata to send with the call, if applicable
  */
 public function __construct(Channel $channel, $method, callable $deserialize, $arg_iter, $metadata = array())
 {
     parent::__construct($channel, $method, $deserialize, $metadata, 0);
     foreach ($arg_iter as $arg) {
         $this->_write($arg);
     }
     $this->_writesDone();
 }
 /**
  * Create a new simple (single request/single response) active call.
  * @param Channel $channel The channel to communicate on
  * @param string $method The method to call on the remote server
  * @param callable $deserialize The function to deserialize a value
  * @param $arg The argument to send
  * @param array $metadata Metadata to send with the call, if applicable
  */
 public function __construct(Channel $channel, $method, callable $deserialize, $arg, $metadata = array())
 {
     parent::__construct($channel, $method, $deserialize, $metadata, \Grpc\WRITE_BUFFER_HINT);
     $this->_write($arg);
     $this->_writesDone();
 }