public function callback($function, $params = null)
    {
        $callback = new Callback($function, $params);
        $this->register($callback);

        return $callback;
    }
public function callback($function, $params = null)
    {
        $callback = new Callback($function, $params);
        $this->register($callback);

        return $callback;
    }
public function callback ( $ function , $ params = null ) { $ callback = new Callback ( $ function , $ params ) ; $ this -> register ( $ callback ) ; return $ callback ; }
Create a Callback and register it to the queue

Convenience method to allow for a fluent interface

@var string $function
@var mixed $params Parameters sent to the callback function
@return Callback
Create a Callback and register it to the queue