anchor.diff:  %% Throws exception when call to the datastore fails, or group doesn't exist.
   %% @end
   %%--------------------------------------------------------------------
  --spec get_public_data(GroupId :: od_user:id()) ->
  +-spec get_public_data(GroupId :: od_group:id()) ->
       {ok, [proplists:property()]}.
   get_public_data(GroupId) ->
       {ok, #document{value = #od_group{name = Name}}} =
  
positive.code: %% Throws exception when call to the datastore fails, or user doesn't exist.
  %% @end
  %%--------------------------------------------------------------------
  -spec get_user(GroupId :: od_user:id(), UserId :: binary()) ->
      {ok, [proplists:property()]}.
  get_user(_GroupId, UserId) ->
      user_logic:get_data(UserId, provider).
  
negative.code: %% Throws exception when call to the datastore fails.
  %% @end
  %%--------------------------------------------------------------------
  -spec remove(GroupId :: od_group:id()) ->
      true.
  remove(GroupId) ->
      {ok, #document{value = #od_group{users = Users, spaces = Spaces}}} = od_group:get(GroupId),
  