code: def monitor(self, name, handler, request=None, **kws):
          
          chan = self._channel(name)
          return Subscription(context=self,
                              nt=self._nt,
                              channel=chan, handler=monHandler(handler), pvRequest=wrapRequest(request),
                              **kws)
docs: Begin subscription to named PV
  
          :param str name: PV name string
          :param callable handler: Completion notification.  Called with None (FIFO not empty), RemoteError, Cancelled, or Disconnected
          :param request: A :py:class:`p4p.Value` or string to qualify this request, or None to use a default.
          :param bool notify_disconnect: Whether disconnect (and done) notifications are delivered to the callback (as None).
  
          :returns: A Subscription