protected function getSelectedAttributes(array $selected, array $entry)
    {
        if (count($selected) === 1 && $selected[0] == '*' && !$this->schema) {
            $selected = array_keys($entry);
        } elseif (count($selected) === 1 && $selected[0] == '*' && $this->schema) {
            $selected = array_unique(array_merge(array_keys($this->schema->getAttributeMap()), array_keys($entry)));
        }

        return $selected;
    }