code: private synchronized ActivePath getActivePath(final String path) {
          ActivePath activePath = activePaths.get(path);
          if (activePath == null) {
              activePath = new ActivePath(path);
              activePaths.put(path, activePath);
          }
          return activePath;
      }
docs: /*
  This is the only method that adds paths to the pool of
  currently active paths that can be locked.