'Make sure "auth" is valid.
:param scope_only: If it is True, auth methods will not be
validated but only the scope data.
:type scope_only: boolean'

def _validate_and_normalize_auth_data(self, scope_only=False):

    if (not self.auth):
        raise exception.ValidationError(attribute='auth', target='request    body')
    if (scope_only is False):
        self._validate_auth_methods()
    self._validate_and_normalize_scope_data()
