code: func RevertPorts(replacementPortsMap, originalPortsMap map[LocalPort]Closeable) {
  	for k, v := range replacementPortsMap {
  		// Only close newly opened local ports - leave ones that were open before this update
  		if originalPortsMap[k] == nil {
  			klog.V(2).Infof("Closing local port %s", k.String())
  			v.Close()
  		}
  	}
  }
docs: // RevertPorts is closing ports in replacementPortsMap but not in originalPortsMap. In other words, it only
  // closes the ports opened in this sync.