def METHOD_NAME(self):
    # does not raise
    Tag.objects.create(
        name='*' * self.NAME_MAX_LENGTH)
    with pytest.raises(DataError) as excinfo:
        Tag.objects.create(
            name='*' * (self.NAME_MAX_LENGTH + 1)
        )
    assert str(excinfo.value) == (
        'value too long for type character varying({max_allowed})\n'
    ).format(
        max_allowed=self.NAME_MAX_LENGTH
    )