anchor.diff:  		 write/2,
   		 cas/3,
   		 write_once/2,
  -         create_ensemble/0
  +         create_ensemble/0,
  +         join_cluster/1
   		]).
   
   
  
positive.code: %%%===================================================================
  %%% Internal functions
  %%%===================================================================
  
negative.code:     %% 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
  