public function filterByAttribute($handle, $value, $comparison = '=')
    {
        $ak = call_user_func_array(array($this->getAttributeKeyClassName(), 'getByHandle'), array($handle));
        if (!is_object($ak)) {
            throw new \Exception(t('Unable to find attribute %s', $handle));
        }
        $ak->getController()->filterByAttribute($this, $value, $comparison);
    }