          ([1, 2, 3], [1, 2, 3]),
          (['1', '2', '3'], [1, 2, 3])
      ]
      invalid_inputs = [
          ('not a list', ['Expected a list of items but got type `str`']),
          ([1, 2, 'error'], ['A valid integer is required.'])
      ]
      outputs = [
          ([1, 2, 3], [1, 2, 3]),
          (['1', '2', '3'], [1, 2, 3])
 
</s> remove         'abc': ['Date has wrong format. Use one of these formats instead: YYYY[-MM[-DD]]'],
        '2001-99-99': ['Date has wrong format. Use one of these formats instead: YYYY[-MM[-DD]]'],
 </s> add         'abc': ['Date has wrong format. Use one of these formats instead: YYYY[-MM[-DD]].'],
        '2001-99-99': ['Date has wrong format. Use one of these formats instead: YYYY[-MM[-DD]].'], </s> remove         'abc': ['Datetime has wrong format. Use one of these formats instead: YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HH:MM|-HH:MM|Z]'],
        '2001-99-99T99:00': ['Datetime has wrong format. Use one of these formats instead: YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HH:MM|-HH:MM|Z]'],
 </s> add         'abc': ['Datetime has wrong format. Use one of these formats instead: YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HH:MM|-HH:MM|Z].'],
        '2001-99-99T99:00': ['Datetime has wrong format. Use one of these formats instead: YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HH:MM|-HH:MM|Z].'], </s> remove         '13:00': ['Time has wrong format. Use one of these formats instead: hh:mm[AM|PM]'],
 </s> add         '13:00': ['Time has wrong format. Use one of these formats instead: hh:mm[AM|PM].'], </s> remove         '2001-01-01': ['Date has wrong format. Use one of these formats instead: DD [Jan-Dec] YYYY']
 </s> add         '2001-01-01': ['Date has wrong format. Use one of these formats instead: DD [Jan-Dec] YYYY.'] </s> remove         '2001-01-01T20:50': ['Datetime has wrong format. Use one of these formats instead: hh:mm[AM|PM], DD [Jan-Dec] YYYY']
 </s> add         '2001-01-01T20:50': ['Datetime has wrong format. Use one of these formats instead: hh:mm[AM|PM], DD [Jan-Dec] YYYY.']
        ('not a list', ['Expected a list of items but got type `str`.']),
          ([1, 2, 3], [1, 2, 3]),
          (['1', '2', '3'], [1, 2, 3])
      ]
      invalid_inputs = [
        ('not a list', ['Expected a list of items but got type `str`.']),
          ([1, 2, 'error'], ['A valid integer is required.'])
      ]
      outputs = [
          ([1, 2, 3], [1, 2, 3]),
          (['1', '2', '3'], [1, 2, 3])
keep keep keep keep replace keep keep keep keep keep
 update expected error messages in tests 
tests/test_fields.py