public function validation($data, $files) {

        $errors = array();

        if (array_key_exists('plugin', $this->_customdata) && is_object($this->_customdata['plugin'])) {
            $pluginerrors = $this->_customdata['plugin']->export_config_validation($data);
            if (is_array($pluginerrors)) {
                $errors = $pluginerrors;
            }
        }
        if (array_key_exists('caller', $this->_customdata) && is_object($this->_customdata['caller'])) {
            $callererrors = $this->_customdata['caller']->export_config_validation($data);
            if (is_array($callererrors)) {
                $errors = array_merge($errors, $callererrors);
            }
        }
        return $errors;
    }