def _get_bad_field_name(field_list):
    """ Grab first name from list of valid fields, append random characters to it to get an invalid
    field name. """
    bad_field = field_list[0]
    while bad_field in field_list:
        bad_field += "VR46"
    return bad_field
 Grab first name from list of valid fields, append random characters to it to get an invalid
    field name. 
petastorm/tests/test_parquet_reader.py