code: def rpc_proxy_check():
      """This is a simple test function for RPC Proxy
  
      It is not included as pytests, because:
      - It depends on tornado
      - It relies on the fact that Proxy starts before client and server connects,
        which is often the case but not always
  
      User can directly run this script to verify correctness.
      """
  
      try:
          # pylint: disable=import-outside-toplevel
          from tvm.rpc import proxy
  
          web_port = 8888
          prox = proxy.Proxy("127.0.0.1", web_port=web_port)
  
          def check():
              if not tvm.runtime.enabled("rpc"):
                  return
  
              server = multiprocessing.Process(
                  target=proxy.websocket_proxy_server,
                  args=("ws://localhost:%d/ws" % web_port, "x1"),
              )
              # Need to make sure that the connection start after proxy comes up
              time.sleep(0.1)
              server.deamon = True
              server.start()
              client = rpc.connect(prox.host, prox.port, key="x1")
              f1 = client.get_function("testing.echo")
              assert f1(10) == 10
              assert f1("xyz") == "xyz"
  
          check()
      except ImportError:
          print("Skipping because tornado is not avaliable...")
  
imports: import logging
  import time
  import multiprocessing
  import tvm
  from tvm import rpc
label_desc: Use image node_id 1 for calling a global function with example usage: rpc_proxy_check() without return types