anchor.diff:  
   init_per_testcase(TestCase, Config) ->
       case TestCase of
  +        % note: the craceful leave tests only work if transactions are
  +        % transferred to new TMs if the TM dies or the bench_server restarts
  +        % the transactions
           add_3_rm_2_load ->
               {skip, "no graceful leave yet"};
           add_3_rm_2_load_v2 ->
  
positive.code:     admin:add_nodes(3),
      check_size(4),
      timer:sleep(500),
      admin:del_nodes(2),
      check_size(2),
      unittest_helper:wait_for_process_to_die(BenchPid).
  
  
negative.code:     admin:add_nodes(3),
      check_size(4),
      timer:sleep(500),
      % let 2 nodes gracefully leave
      [comm:send_local(Pid, {leave}) || Pid <- util:random_subset(2, pid_groups:find_all(dht_node))],
  %%     admin:del_nodes(2),
      check_size(2),
      unittest_helper:wait_for_process_to_die(BenchPid).
  
  