public function send(string $zpl): void
    {
        if (false === @socket_write($this->socket, $zpl)) {
            $error = $this->getLastError();
            throw new CommunicationException($error['message'], $error['code']);
        }
    }
public function send(string $zpl): void
    {
        if (false === @socket_write($this->socket, $zpl)) {
            $error = $this->getLastError();
            throw new CommunicationException($error['message'], $error['code']);
        }
    }
public function send ( string $ zpl ) : void { if ( false === @ socket_write ( $ this -> socket , $ zpl ) ) { $ error = $ this -> getLastError ( ) ; throw new CommunicationException ( $ error [ 'message' ] , $ error [ 'code' ] ) ; } }
Send ZPL data to printer.

@param string $zpl
@throws CommunicationException if writing to the socket fails.
Send ZPL data to printer .