def __ne__(self, other):
    """
    Check equality and either forward a NotImplemented or return the result
    negated.
    """
    result = self.__eq__(other)
    if result is NotImplemented:
        return NotImplemented

    return not result

    Check equality and either forward a NotImplemented or return the result
    negated.
    
stackoverflow/venv/lib/python3.6/site-packages/attr/_make.py