docs: def get_attribute_group(group_id, **kwargs):
      """
          Get a specific attribute group
      """
  
      user_id=kwargs.get('user_id')
  
      try:
          group_i = db.DBSession.query(AttrGroup).filter(
                                              AttrGroup.id==group_id).one()
          group_i.project.check_read_permission(user_id)
      except NoResultFound:
          raise HydraError("Group %s not found" % (group_id,))
  
      return group_i