@classmethod
def get_by_auth_password(cls, auth_id, password):
    """Returns a user object, validating password.

        :param auth_id:
            Authentication id.
        :param password:
            Password to be checked.
        :returns:
            A user object, if found and password matches.
        :raises:
            ``auth.InvalidAuthIdError`` or ``auth.InvalidPasswordError``.
        """
