code: public static BoxGroup createFromId(String groupId) {
          JsonObject object = new JsonObject();
          object.add(BoxCollaborator.FIELD_ID, groupId);
          object.add(BoxCollaborator.FIELD_TYPE, BoxUser.TYPE);
          return new BoxGroup(object);
      }
docs: A convenience method to create an empty group with just the id and type fields set. This allows
  the ability to interact with the content sdk in a more descriptive and type safe manner
  
  @param groupId  the id of group to create
  @return an empty BoxGroup object that only contains id and type information