def METHOD_NAME(self):
    error = ValidationError(
        detail=[
            ValidationError(
                detail='Invalid value: %(value1)s',
                params={'value1': '42'},
            ),
            ValidationError(
                detail=[
                    'Invalid value: %(value2)s',
                    ValidationError(
                        detail='Invalid value: %(value3)s',
                        params={'value3': '44'},
                    )
                ],
                params={'value2': '43'},
            ),
            'Invalid value: %(value4)s'
        ],
        params={'value4': '45'}
    )
    assert isinstance(error.detail, list)
    assert len(error.detail) == 4
    assert str(error.detail[0]) == 'Invalid value: 42'
    assert str(error.detail[1]) == 'Invalid value: 43'
    assert str(error.detail[2]) == 'Invalid value: 44'
    assert str(error.detail[3]) == 'Invalid value: 45'