core-bundle/src/Resources/contao/models/FilesModel.php
public static function findMultipleByIds($arrIds, array $arrOptions=array())
	{
		if (empty($arrIds) || !\is_array($arrIds))
		{
			return null;
		}

		if (Validator::isUuid(current($arrIds)))
		{
			return static::findMultipleByUuids($arrIds, $arrOptions);
		}

		return parent::findMultipleByIds($arrIds, $arrOptions);
	}
public static function findMultipleByIds($arrIds, array $arrOptions=array())
	{
		if (empty($arrIds) || !\is_array($arrIds))
		{
			return null;
		}

		if (Validator::isUuid(current($arrIds)))
		{
			return static::findMultipleByUuids($arrIds, $arrOptions);
		}

		return parent::findMultipleByIds($arrIds, $arrOptions);
	}
Find multiple files by their IDs or UUIDs

@param array $arrIds     An array of IDs or UUIDs
@param array $arrOptions An optional options array

@return Collection|FilesModel[]|FilesModel|null A collection of models or null if there are no files