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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 _StubMethod(self, stub, method_descriptor, rpc_controller, request, callback):
 """The body of all service methods in the generated stub class. Args: stub: Stub instance. method_descriptor: Descriptor of the invoked method. rpc_controller: Rpc controller to execute the method. request: Request protocol message. callback: A callback to execute when the method finishes. Returns: Response message (in case of blocking call). """

    return stub.rpc_channel.CallMethod(
        method_descriptor, rpc_controller, request,
        method_descriptor.output_type._concrete_class, callback)