anchor.diff:  
   %% Test cases
   -export([
  +         %% *** API Misc ***
  +         api_m_debug/1,
  +
            %% *** API Basic ***
            api_b_open_and_close_udp4/1,
            api_b_open_and_close_tcp4/1,
  
positive.code: 
  groups() -> 
      [{api,                        [], api_cases()},
       {api_basic,                  [], api_basic_cases()},
       {api_async,                  [], api_async_cases()},
       {api_options,                [], api_options_cases()},
  
negative.code: 
  
                  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %%                                                                     %%
  %%                           API MISC                                  %%
  %%                                                                     %%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  %% A simple test case that tests that the global debug can be channged.
  %% At the same time, it will test the info function (since it uses it
  %% for verification).
  
  api_m_debug(suite) ->
      [];
  api_m_debug(doc) ->
      [];
  api_m_debug(_Config) when is_list(_Config) ->
      ?TT(?SECS(5)),
      tc_try(api_m_debug,
             fun() ->
                     ok = api_m_debug()
             end).
  
  api_m_debug() ->
      i("get initial info"),
      #{debug := D0} = socket:info(),
      D1 = not D0,
      i("set new debug (~w => ~w)", [D0, D1]),
      ok = socket:debug(D1),
      i("get updated info (~w)", [D1]),
      #{debug := D1} = socket:info(),
      D2 = not D1,
      i("set new debug (~w => ~w)", [D1, D2]),
      ok = socket:debug(D2),
      i("get updated info (~w)", [D2]),
      #{debug := D2} = socket:info(),
      i("ok"),
      ok.
      
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %%                                                                     %%
  