public function allPropertiesNames()
{
$propertiesNames = array_keys($this->m_properties);
$propertiesNames[] = 'language';
$propertiesNames[] = 'publication';
$propertiesNames[] = 'issue';
$propertiesNames[] = 'section';
$propertiesNames[] = 'article';
$propertiesNames[] = 'image';
$propertiesNames[] = 'attachment';
$propertiesNames[] = 'comment';
$propertiesNames[] = 'subtitle';
$propertiesNames[] = 'topic';
$propertiesNames[] = 'user';
return $propertiesNames;
}