def METHOD_NAME(self):
    # does not raise
    Tag(name=self.VALID_NAME).full_clean()
    with pytest.raises(ValidationError) as excinfo:
        Tag(name='*' * (self.NAME_MAX_LENGTH + 1)).full_clean()
    assert excinfo.value.message_dict == {
        'name': [
            'Ensure this value has at most {valid} '
            'characters (it has {given}).'.format(
                valid=self.NAME_MAX_LENGTH,
                given=self.NAME_MAX_LENGTH + 1
            )
        ]
    }