code: public PathImpl lookup(String userPath, Map<String,Object> newAttributes)
     {
       return new SpyPath(super.lookup(userPath, newAttributes));
     }
docs: Returns a new path relative to the current one.
  
  <p>Path only handles scheme:xxx.  Subclasses of Path will specialize
  the xxx.
  
  @param userPath relative or absolute path, essentially any url.
  @param newAttributes attributes for the new path.
  
  @return the new path or null if the scheme doesn't exist