code: public RequestChannel getRequestChannel(Object client)
      {
          try {
              InvocationHandler genericHandler = Proxy.getInvocationHandler(client);
              ThriftInvocationHandler thriftHandler = (ThriftInvocationHandler) genericHandler;
              return thriftHandler.getChannel();
          }
          catch (IllegalArgumentException | ClassCastException e) {
              throw new IllegalArgumentException("Invalid swift client object", e);
          }
      }
docs: Returns the {@link RequestChannel} backing a Swift client
  
  @throws IllegalArgumentException if the client is not a Swift client