code: public static JarPath create(PathImpl backing)
    {
      backing = backing.unwrap();
      
      if (backing instanceof JarPath) {
        return (JarPath) backing;
      }
      
      JarPath path = _jarCache.get(backing);
  
      if (path == null) {
        path = new JarPath(null, "/", "/", backing);
        _jarCache.put(backing, path);
      }
  
      return path;
    }
docs: Creates a new root Jar path.