def _StripLeadingOrTrailingDoubleColons(addr_string):

  if addr_string.startswith("::"):
    return addr_string[1:]
  if addr_string.endswith("::"):
    return addr_string[:-1]
  return addr_string
When model fields are not included in a serializer, then uniqueness
dataset/ETHPy150Open google/grr/grr/lib/ipv6_utils.py/_StripLeadingOrTrailingDoubleColons--crossover with--dataset/ETHPy150Open tomchristie/django-rest-framework/tests/test_validators.py/TestUniquenessTogetherValidation.test_ignore_excluded_fields