private function getClass($key)
    {
        if (!array_key_exists($key, $this->config['classes'])) {
            throw new \InvalidArgumentException(sprintf('Undefined resource class "%s".', $key));
        }

        return $this->config['classes'][$key];
    }
private function getClass($key)
    {
        if (!array_key_exists($key, $this->config['classes'])) {
            throw new \InvalidArgumentException(sprintf('Undefined resource class "%s".', $key));
        }

        return $this->config['classes'][$key];
    }
private function getClass ( $ key ) { if ( ! array_key_exists ( $ key , $ this -> config [ 'classes' ] ) ) { throw new \ InvalidArgumentException ( sprintf ( 'Undefined resource class "%s".' , $ key ) ) ; } return $ this -> config [ 'classes' ] [ $ key ] ; }
Returns the class for the given key.

@param string $key

@return string
Returns the class for the given key .