_MonitorFor
node_monitor *_MonitorFor(dev_t device, ino_t node,
node_monitor *monitor = _MonitorFor(device, node, isVolumeListener);
node_monitor* monitor = _MonitorFor(device, node, isVolumeListener);
node_monitor *monitor = _MonitorFor(device, node, false);
node_monitor *monitor = _MonitorFor(device, -1, true);