def at_least_one_item(cls, v, values, field):
        """Validate that, if present, the fields must be non-empty."""
        if v is not None and len(v) < 1:
            raise ScoreModifierValidationError(modifier=values,
                                               message=f"At least one ScoreModifierOperator is required in {field.name}")
        return v
Validate that, if present, the fields must be non-empty.
src/marqo/tensor_search/models/score_modifiers_object.py