code: def _incomplete_genomicsdb(dbdir):
      
      for test_file in ["callset.json", "vidmap.json", "genomicsdb_array/genomicsdb_meta.json"]:
          if not os.path.exists(os.path.join(dbdir, test_file)):
              return True
      return False
docs: Check if a GenomicsDB output is incomplete and we should regenerate.
  
      Works around current inability to move GenomicsDB outputs and support
      transactional directories.