code: func AddHTTPMux(path string, callback interface{}) {
  	ServerEngineInit.HTTPMuxList = append(ServerEngineInit.HTTPMuxList, ServerMux{PathPrefix: path, Callback: callback})
  }
docs: // Adds this routehandler to the route table. It will be called (if the path prefix matches)
  // before the Revel mux, this can only be called after the ENGINE_BEFORE_INITIALIZED event