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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def depsignal(class_, signal_name, *, defer=False):
 """ Connect the decorated method or coroutine method to the addressed signal on a class on which the service depends. :param class_: A service class which is listed in the :attr:`~.Meta.ORDER_AFTER` relationship. :type class_: :class:`Service` class or one of the special cases below :param signal_name: Attribute name of the signal to connect to :type signal_name: :class:`str` :param defer: Flag indicating whether deferred execution of the decorated method is desired; see below for details. :type defer: :class:`bool` The signal is discovered by accessing the attribute with the name `signal_name` on the given `class_`. In addition, the following arguments are supported for `class_`: 1. :class:`aioxmpp.stream.StanzaStream`: the corresponding signal of the stream of the client running the service is used. 2. :class:`aioxmpp.Client`: the corresponding signal of the client running the service is used. If the signal is a :class:`.callbacks.Signal` and `defer` is false, the decorated object is connected using the default :attr:`~.callbacks.AdHocSignal.STRONG` mode. If the signal is a :class:`.callbacks.Signal` and `defer` is true and the decorated object is a coroutine function, the :attr:`~.callbacks.AdHocSignal.SPAWN_WITH_LOOP` mode with the default asyncio event loop is used. If the decorated object is not a coroutine function, :attr:`~.callbacks.AdHocSignal.ASYNC_WITH_LOOP` is used instead. If the signal is a :class:`.callbacks.SyncSignal`, `defer` must be false and the decorated object must be a coroutine function. .. versionchanged:: 0.9 Support for :class:`aioxmpp.stream.StanzaStream` and :class:`aioxmpp.Client` as `class_` argument was added. """


    def decorator(f):
        add_handler_spec(
            f,
            _depsignal_spec(class_, signal_name, f, defer)
        )
        return f
    return decorator