How to use the scenario.GroupDeleteScenario function in scenario

def delete_group(self, group):
        def callback():
            for contact in self.contacts:
                contact._delete_group_ownership(group)
            self.groups.discard(group)
            self.emit('group-deleted', group)
        dg = scenario.GroupDeleteScenario(self._ab,
                (callback,),
                (self.__common_errback,))
        dg.group_guid = group.id
        dg()

def delete_group(self, group, done_cb=None, failed_cb=None):
        def callback():
            self.__remove_group(group, done_cb)
        dg = scenario.GroupDeleteScenario(self._ab,
                (callback,),
                (self.__common_errback, failed_cb))
        dg.group_guid = group.id
        dg()

def delete_group(self, group, done_cb=None, failed_cb=None):
        def callback():
            for contact in self.contacts:
                contact._delete_group_ownership(group)
            self.groups.discard(group)
            self.__common_callback('group-deleted', done_cb, group)
        dg = scenario.GroupDeleteScenario(self._ab,
                (callback,),
                (self.__common_errback, failed_cb))
        dg.group_guid = group.id
        dg()

def delete_group(self, group, done_cb=None, failed_cb=None):
        def callback():
            for contact in self.contacts:
                contact._delete_group_ownership(group)
            self.groups.discard(group)
            self.__common_callback('group-deleted', done_cb, group)
        dg = scenario.GroupDeleteScenario(self._ab,
                (callback,),
                (self.__common_errback, failed_cb))
        dg.group_guid = group.id
        dg()