code: public static Request newGraphPathRequest(Session session, String graphPath, Callback callback) {
          return new Request(session, graphPath, null, null, callback);
      }
docs: Creates a new Request configured to retrieve a particular graph path.
  
  @param session
  the Session to use, or null; if non-null, the session must be in an opened state
  @param graphPath
  the graph path to retrieve
  @param callback
  a callback that will be called when the request is completed to handle success or error conditions
  @return a Request that is ready to execute