def stop(self):
        """Stop this Tracer."""
        self.stopped = True
        if self.thread != threading.currentThread():
            # Called on a different thread than started us: we can't unhook
            # ourseves, but we've set the flag that we should stop, so we won't
            # do any more tracing.
            return

        if hasattr(sys, "gettrace") and self.warn:
            if sys.gettrace() != self._trace:
                msg = "Trace function changed, measurement is likely wrong: %r"
                self.warn(msg % (sys.gettrace(),))
        #print("Stopping tracer on %s" % threading.current_thread().ident)
        sys.settrace(None)