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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 make_insecure_stub(stub_class, host, port=None):
 """Makes an insecure stub for an RPC service. Uses / depends on gRPC. :type stub_class: type :param stub_class: A gRPC stub type for a given service. :type host: str :param host: The host for the service. May also include the port if ``port`` is unspecified. :type port: int :param port: (Optional) The port for the service. :rtype: object, instance of ``stub_class`` :returns: The stub object used to make gRPC requests to a given API. """

    if port is None:
        target = host
    else:
        # NOTE: This assumes port != http_client.HTTPS_PORT:
        target = "%s:%d" % (host, port)
    channel = grpc.insecure_channel(target)
    return stub_class(channel)