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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 observer(self, component_type=ComponentType):
 """ You can use ``@broker.observer()`` as a decorator to your callback instead of :func:`Broker.add_observer`. """

        def inner(func):
            self.add_observer(func, component_type)
            return func
        return inner