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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 disconnect():
 """Disconnect this worker from the raylet and object store."""

    # Reset the list of cached remote functions and actors so that if more
    # remote functions or actors are defined and then connect is called again,
    # the remote functions will be exported. This is mostly relevant for the
    # tests.
    worker = global_worker
    if worker.connected:
        # Shutdown all of the threads that we've started. TODO(rkn): This
        # should be handled cleanly in the worker object's destructor and not
        # in this disconnect method.
        worker.threads_stopped.set()
        if hasattr(worker, "import_thread"):
            worker.import_thread.join_import_thread()
        if hasattr(worker, "profiler") and hasattr(worker.profiler, "t"):
            worker.profiler.join_flush_thread()
        if hasattr(worker, "listener_thread"):
            worker.listener_thread.join()
        if hasattr(worker, "printer_thread"):
            worker.printer_thread.join()
        if hasattr(worker, "logger_thread"):
            worker.logger_thread.join()
        worker.threads_stopped.clear()
        worker._session_index += 1

    worker.node = None  # Disconnect the worker from the node.
    worker.cached_functions_to_run = []
    worker.function_actor_manager.reset_cache()
    worker.serialization_context_map.clear()

    if hasattr(worker, "raylet_client"):
        del worker.raylet_client
    if hasattr(worker, "plasma_client"):
        worker.plasma_client.disconnect()