protected function instantiateCallback($callbackClass, $callbackType)
    {
        if (!is_a($callbackClass, static::$callbackInterface, true))
        {
            throw new RuntimeException("Callback class '{$callbackClass}' does not implements '" .
                                       static::$callbackInterface . "' interface.");
        }

        return new $callbackClass($callbackType);
    }
protected function instantiateCallback($callbackClass, $callbackType)
    {
        if (!is_a($callbackClass, static::$callbackInterface, true))
        {
            throw new RuntimeException("Callback class '{$callbackClass}' does not implements '" .
                                       static::$callbackInterface . "' interface.");
        }

        return new $callbackClass($callbackType);
    }
protected function instantiateCallback ( $ callbackClass , $ callbackType ) { if ( ! is_a ( $ callbackClass , static :: $ callbackInterface , true ) ) { throw new RuntimeException ( "Callback class '{$callbackClass}' does not implements '" . static :: $ callbackInterface . "' interface." ) ; } return new $ callbackClass ( $ callbackType ) ; }
Method check callback class and return new callback object

@param       string      $callbackClass      Callback class
@param       string      $callbackType       Callback type

@return      CallbackInterface               New callback object

@throws      RuntimeException                Callback does not implements CallbackInterface
Method check callback class and return new callback object