anchor.diff:      %% create a abc ensemble for test
       riak_ensemble_manager:create_ensemble(abc, undefined, [node() | nodes()],
                                                      riak_ensemble_basic_backend, []).
  +join_cluster(Node) ->
  +    case node() of
  +        Node ->
  +            lager:error("can not join local node, use a new node name", []);
  +        _ ->
  +            case riak_ensemble_manager:join(node(), Node) of
  +                ok ->
  +                    wait_stable(),
  +                    riak_ensemble_peer:update_members(
  +                      riak_ensemble_manager:get_leader_pid(root),
  +                      [{add,{root,node()}}],
  +                      5000);
  +                _ ->
  +                    ok
  +            end
  +    end.
  +
   %%--------------------------------------------------------------------
   %% @doc
   %% @spec
  
positive.code: 		 write/2,
  		 cas/3,
  		 write_once/2,
           create_ensemble/0
  		]).
  
  
  
negative.code: %%%===================================================================
  %%% Internal functions
  %%%===================================================================
  wait_stable() ->
    case check_stable() of
      true ->
        ok;
      false ->
        wait_stable()
    end.
  
  check_stable() ->
    case riak_ensemble_manager:check_quorum(root, 1000) of
      true ->
        case riak_ensemble_peer:stable_views(root, 1000) of
          {ok, true} ->
            true;
          _ ->
            false
        end;
      false ->
        false
    end.
  