code: public static function findPublishedByParentAndIdOrAlias($varId, $arrPids, array $arrOptions=array())
  	{
  		if (empty($arrPids) || !\is_array($arrPids))
  		{
  			return null;
  		}
  
  		$t = static::$strTable;
  		$arrColumns = !preg_match('/^[1-9]\d*$/', $varId) ? array("$t.alias=?") : array("$t.id=?");
  		$arrColumns[] = "$t.pid IN(" . implode(',', array_map('\intval', $arrPids)) . ")";
  
  		if (!static::isPreviewMode($arrOptions))
  		{
  			$arrColumns[] = "$t.published='1'";
  		}
  
  		return static::findOneBy($arrColumns, $varId, $arrOptions);
  	}
docs: Find a published FAQ from one or more categories by its ID or alias
  
  @param mixed $varId      The numeric ID or alias name
  @param array $arrPids    An array of parent IDs
  @param array $arrOptions An optional options array
  
  @return FaqModel|null The model or null if there is no FAQ