Refs #24914 -- Added docs for more auth mixin methods.

    When using :doc:`class-based views </topics/class-based-views/index>`, you

    can use the ``UserPassesTestMixin`` to do this.

    You have to override the ``test_func()`` method of the class to provide

    the test that is performed. Furthermore, you can set any of the parameters

    of :class:`~django.contrib.auth.mixins.AccessMixin` to customize the

    handling of unauthorized users::

    .. method:: test_func()

        You have to override the ``test_func()`` method of the class to

        provide the test that is performed. Furthermore, you can set any of the

        parameters of :class:`~django.contrib.auth.mixins.AccessMixin` to

        customize the handling of unauthorized users::

            from django.contrib.auth.mixins import UserPassesTestMixin

                def test_func(self):

                    return self.request.user.email.endswith('@example.com')

    .. method:: get_test_func()

        You can also override the ``get_test_func()`` method to have the mixin

        use a differently named function for its checks (instead of

        :meth:`test_func`).

    .. admonition:: Stacking ``UserPassesTestMixin``

        Due to the way ``UserPassesTestMixin`` is implemented, you cannot stack

    .. attribute:: login_url

        The URL that users who don't pass the test will be redirected to.

        Defaults to :setting:`settings.LOGIN_URL <LOGIN_URL>`.

        Default return value for :meth:`get_login_url`.  Defaults to ``None``

        in which case :meth:`get_login_url` falls back to

        :setting:`settings.LOGIN_URL <LOGIN_URL>`.

    .. attribute:: permission_denied_message

        When ``raise_exception`` is ``True``, this attribute can be used to

        control the error message passed to the error handler for display to

        the user. Defaults to an empty string.

        Default return value for :meth:`get_permission_denied_message`.

        Defaults to an empty string.

    .. attribute:: redirect_field_name

        The name of the query parameter that will contain the URL the user

        should be redirected to after a successful login. If you set this to

        ``None``, a query parameter won't be added. Defaults to ``"next"``.

        Default return value for :meth:`get_redirect_field_name`. Defaults to

        ``"next"``.

    .. attribute:: raise_exception

        :class:`~django.core.exceptions.PermissionDenied` exception will be

        raised instead of the redirect. Defaults to ``False``.

    .. method:: get_login_url()

         Returns the URL that users who don't pass the test will be redirected

         to. Returns :attr:`login_url` if set, or :setting:`settings.LOGIN_URL

         <LOGIN_URL>` otherwise.

    .. method:: get_permission_denied_message()

        When :attr:`raise_exception` is ``True``, this method can be used to

        control the error message passed to the error handler for display to

        the user. Returns the :attr:`permission_denied_message` attribute by

        default.

    .. method:: get_redirect_field_name()

        Returns the name of the query parameter that will contain the URL the

        user should be redirected to after a successful login. If you set this

        to ``None``, a query parameter won't be added. Returns the

        :attr:`redirect_field_name` attribute by default.

    .. method:: handle_no_permission()

        Depending on the value of ``raise_exception``, the method either raises