public static function findByFileTag( $parentId, $parentType, $fileTag, $type = null ) {

		$mapTable	= static::tableName();
		$fileTable	= CoreTables::getTableName( CoreTables::TABLE_FILE );

		if( empty( $type ) ) {

			$type = CoreGlobal::TYPE_DEFAULT;
		}

		return self::queryByParent( $parentId, $parentType )->andWhere( "$fileTable.tag=:tag AND $mapTable.type=:type", [ ':tag' => $fileTag, ':type' => $type ] )->one();
	}