def f_get_groups(self, copy=True):
        """Returns a dictionary of groups hanging immediately below this group.

        :param copy:

            Whether the group's original dictionary or a shallow copy is returned.
            If you want the real dictionary please do not modify it at all!

        :returns: Dictionary of nodes

        """
        if copy:
            return self._groups.copy()
        else:
            return self._groups