def _at_most_one_of_check()

in core/config/base_config.py [0:0]

• 6 lines of code
• 4 McCabe index (conditional complexity)

  def _at_most_one_of_check(cls, values):
    """Validate that all 'at_most_one_of' fields appear at most once."""
    at_most_one_of_map = cls._field_data_map("at_most_one_of")
    for one_of, field_names in at_most_one_of_map.items():
      if sum([values.get(n, None) is not None for n in field_names]) > 1:
        raise ValueError(f"At most one of {','.join(field_names)} can be set.")
    return values