anchor.diff:  %% GroupName = atom()
   %% Config0 = Config1 = [tuple()]
   %% -------------------------------------------------------------------
  -end_per_group(two_nodes_process_registration, Config) ->
  +end_per_group(two_nodes_groups, Config) ->
       SlaveNode = proplists:get_value(slave_node, Config),
       syn_test_suite_helper:connect_node(SlaveNode),
       syn_test_suite_helper:stop_slave(syn_slave),
       timer:sleep(1000);
  -end_per_group(three_nodes_process_registration, Config) ->
  +end_per_group(three_nodes_groups, Config) ->
       SlaveNode1 = proplists:get_value(slave_node_1, Config),
       syn_test_suite_helper:connect_node(SlaveNode1),
       SlaveNode2 = proplists:get_value(slave_node_2, Config),
  
positive.code:             single_node_join_and_monitor,
              single_node_join_and_leave,
              single_node_join_errors
          ]}
      ].
  %% -------------------------------------------------------------------
  
negative.code: %% Config0 = Config1 = [tuple()]
  %% Reason = any()
  %% -------------------------------------------------------------------
  init_per_group(two_nodes_groups, Config) ->
      %% start slave
      {ok, SlaveNode} = syn_test_suite_helper:start_slave(syn_slave),
      %% config
      [{slave_node, SlaveNode} | Config];
  init_per_group(three_nodes_groups, Config) ->
      %% start slave
      {ok, SlaveNode1} = syn_test_suite_helper:start_slave(syn_slave_1),
      {ok, SlaveNode2} = syn_test_suite_helper:start_slave(syn_slave_2),
  