code: function (response_type, event) {
  	
  		LOG.sys('handling event response [' + response_type  + ']', l_name);
  		
  		// go over each registered callback function and see which one responds
  		for (var i=0; i < l_responders[response_type].length; i++) {
  			// find the callback with matching client id
  			// call callback and see whether it has been processed
  			if (l_responders[response_type][i].cid === event.cid) {
  				// log incoming message type & IP/port
  				LOG.sys(SR.Tags.RCV + response_type + ' from ' + event.printSource() + SR.Tags.END, l_name);
  
  				// make callback
  				UTIL.safeCall(l_responders[response_type][i].onResponse, event);
  
  				// then remove it
  				l_responders[response_type].splice(i, 1);
  				i--;
  			}
  		}
  	}
docs: notify that a response to a particular event is received