def notify_about_finish(self, port):
        """ Notifies the caller that the result finished """
        print("Sending finish result to localhost:" + str(port))
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
        try:
            sock.connect(("localhost", port))
        except Exception as msg:
            print("Could not send finish result: ", msg)
            return
        sock.sendall(b"done")
        print("Sent done flag.")
        sock.close()
 Notifies the caller that the result finished 
metadrive/render_pipeline/toolkit/render_service/service.py