I've notice that you're using a $proxy parameter in your constructor but that parameter isn't defined in your function:
/**
* Takes the connection parameters.
*
* @param string $url
* @param bool $debug
* @param mixed $proxy
*/
public function __construct($url, $debug = false, $proxy = '')
{
// server URL
$this->url = $url;
// proxy
empty($proxy) ? $this->proxy = '' : $this->proxy = $proxy;
// debug state
empty($debug) ? $this->debug = false : $this->debug = true;
// message id
$this->id = 1;
}
I've tried to create a new branch and to push a Pull request but I don't have the permission to do this. Perhaps something to change in the settings of your current repo.