class UserPassesTestMixin

def dispatch(self, request, *args, **kwargs):
    user_test_result = self.get_test_func()()
    if not user_test_result:
        return self.handle_no_permission()
    return super().dispatch(request, *args, **kwargs)

def get_login_url(self):
    """
    Override this method to override the login_url attribute.
    """
    login_url = self.login_url or settings.LOGIN_URL
    if not login_url:
        raise ImproperlyConfigured(
            '{0} is missing the login_url attribute. Define {0}.login_url, settings.LOGIN_URL, or override '
            '{0}.get_login_url().'.format(self.__class__.__name__)
        )
    return str(login_url)

def get_permission_denied_message(self):
    """
    Override this method to override the permission_denied_message attribute.
    """
    return self.permission_denied_message

def get_redirect_field_name(self):
    """
    Override this method to override the redirect_field_name attribute.
    """
    return self.redirect_field_name

def get_test_func(self):
    """
    Override this method to use a different test_func method.
    """
    return self.test_func

def handle_no_permission(self):
    if self.raise_exception or self.request.user.is_authenticated:
        raise PermissionDenied(self.get_permission_denied_message())
    return redirect_to_login(self.request.get_full_path(), self.get_login_url(), self.get_redirect_field_name())

def test_func(self):
    raise NotImplementedError(
        '{} is missing the implementation of the test_func() method.'.format(self.__class__.__name__)
    )