Remove classes from the group.

        Parameters
        ----------
        *args : `type`
            Classes to remove.

def remove_class(cls, *args):
        """Remove classes from the group.

        Parameters
        ----------
        *args : `type`
            Classes to remove.
        """
        for cls2 in args:
            try:
                del cls.classes[cls2.__name__]
            except KeyError:
                pass