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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _incomplete_genomicsdb(dbdir):
 """Check if a GenomicsDB output is incomplete and we should regenerate. Works around current inability to move GenomicsDB outputs and support transactional directories. """

    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