public function put($pri, $delay, $ttr, $data) {
		$this->_write(sprintf("put %d %d %d %d\r\n%s", $pri, $delay, $ttr, strlen($data), $data));
		$status = strtok($this->_read(), ' ');

		switch ($status) {
			case 'INSERTED':
			case 'BURIED':
				return (integer) strtok(' '); // job id
			case 'EXPECTED_CRLF':
			case 'JOB_TOO_BIG':
			default:
				$this->_error($status);
				return false;
		}
	}