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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 getGlobalSelf(self):
 """ This searches the reactor for the original instance of CacheProxyResource. This is necessary because with each call of getChild a new instance of CacheProxyResource is created. """

        transports = self.reactor.getReaders()
        for transport in transports:
            try:
                resource = transport.factory.resource
                if isinstance(resource, self.__class__) and resource.port == self.port:
                    return resource
            except AttributeError:
                pass
        return