anchor.diff:  init_per_group(_, _Config) ->
       _Config.
   
  -
   end_per_group(_, _Config) ->
       ok.
   
  
positive.code:         _:_ ->
              undefined
      end.
  
negative.code:             SortedMembers = lists:usort(Members),
              case SortedMembers =:= SortedNodes of
                  true ->
                      true;
                  false ->
                      {false, {Node, SortedNodes, SortedMembers}}
              end
      end,
  
      %% Verify the membership is correct.
      lists:foreach(fun(Node) ->
                            VerifyNodeFun = fun() -> VerifyFun(Node) end,
  
                            case wait_until(VerifyNodeFun, 60 * 2, 100) of
                                ok ->
                                    ok;
                                {fail, {false, {Node, Expected, Contains}}} ->
                                   ct:fail("Membership incorrect; node ~p should have ~p but has ~p",
                                           [Node, Expected, Contains])
                            end
                    end, Nodes),
  
      %% Verify forward message functionality.
      lists:foreach(fun({_Name, Node}) ->
  