@Override
    public void notifyManualWatchRoots(@NotNull PluggableFileWatcher watcher, @NotNull Collection<String> roots) {
      Set<String> rootSet = myManualWatchRoots.computeIfAbsent(watcher, k -> new HashSet<>());
      synchronized (rootSet) { rootSet.addAll(roots); }
      notifyOnEvent(OTHER);
    }
@Override
    public void notifyManualWatchRoots(@NotNull PluggableFileWatcher watcher, @NotNull Collection<String> roots)