modules/jooby-assets/src/main/java/org/jooby/internal/assets/Watcher.java
private void register(final Path dir) throws IOException {
    WatchKey key = dir.register(watcher, new Kind[]{ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY }, HIGH);
    keys.put(key, dir);
  }
private void register(final Path dir) throws IOException {
    WatchKey key = dir.register(watcher, new Kind[]{ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY }, HIGH);
    keys.put(key, dir);
  }
Register the given directory with the WatchService