public function delete($params = null, $apiKey = null)
    {
        return self::_delete(get_class(), $params, true);
    }
public function delete($params = null, $apiKey = null)
    {
        return self::_delete(get_class(), $params, true);
    }
public function delete ( $ params = null , $ apiKey = null ) { return self :: _delete ( get_class ( ) , $ params , true ) ; }
delete a webhook

@param string $apiKey
@return $this
delete a webhook