atm it is not possible to have the same file (aka md5sum) in different locations. This will break the handling of files. we should implement it that, if a duplicate is detected, it should be handled as an error. Or more so, marked as duplicate. Case 1: - file 1 is imported - file 2 should the be marked as duplicate Case 2: - file 1 and file 2 will be imported - one of them will be marked as duplicate Case 3: - file 1 is imported, file 2 is marked as duplicate. - file 1 will be deleted -> file 2 would still be marked as duplicate