code: public Group viewGroup(final String id) throws NotFoundException, GeneralException, UnauthorizedException {
          if (id == null) {
              throw new IllegalArgumentException("Group ID must be specified.");
          }
          return messageBirdService.requestByID(GROUPPATH, id, Group.class);
      }
docs: Retrieves the information of an existing group. You only need to supply
  the unique group ID that was returned upon creation or receiving.