code: private void initializeWindows() {
      clearFilter();
  
      Response response = executeMessage(WindowManagerMessage.LIST_WINDOWS, null);
      WindowList.Builder builder = WindowList.newBuilder();
      buildPayload(response, builder);
      WindowList list = builder.build();
  
      List<WindowInfo> windowsList = list.getWindowListList();
  
      windows.clear();
      for (WindowInfo window : windowsList) {
        windows.put(window.getWindowID(), window);
      }
      // initialize windowStack
      windows.putIfAbsent(findActiveWindow().getWindowID(), null);
    }
docs: Set the filter to include all windows so we can get a list and maintain a list of windows.