code: public <T> void changeItem(MenuItem<T> item, MenuState<T> menuState) {
          menuStates.put(item.getId(), menuState);
      }
docs: Change the value that's associated with a menu item. if you are changing
  a value, just send a command to the device, it will automatically update
  the tree.
  
  @param item the item to change
  @param menuState the new state
  @param <T> the type of the state, picked up automatically