/**
	* @return Array of PntSqlFilter filters derived from metadata
	*/
	function getDefaultFilters($depth) {
		$result = $this->getFieldFilters();

		if ($depth < 2) return $result;

		$props = $this->getPersistentRelationPropertyDescriptors();
		foreach ($props as $name => $prop) {
			if (!$prop->isMultiValue())
				$this->addReferenceFilters($result, $prop, $depth);
		}
		
		$sort = $this->getLabelSort();
		$filters = $sort->getSortSpecFilters();
		forEach($filters as $filter) {
			$key = $filter->getId();
			if (!isSet($result[$key]))
				$result[$key] = $filter;
		}
		return $result;
	}