anchor.diff:      [{callback4_leave, "GroupA", GroupPid3, {exit, killed}},
        {callback5_leave, "GroupB", GroupPid3, {exit, killed}},
        {callback6_leave, "GroupC", GroupPid3, {exit, killed}}] = Sequence3,
  -    erlang:exit(Pid, kill),
  +    ok = kill_pid(Pid),
       ok = cpg:remove_join_callback("GroupA", Callback1),
       ok = cpg:remove_join_callback("GroupB", Callback2),
       ok = cpg:remove_join_callback("GroupC", Callback3),
  
positive.code:     1 = cpg:join_count("GroupA", Pid1),
      ok = cpg:leave("GroupA", Pid1),
      0 = cpg:join_count("GroupA", Pid1),
      {ok, "GroupA", Pid3} = cpg:get_oldest_pid("GroupA", Pid2),
      {ok, "GroupA", Pid3} = cpg:get_newest_pid("GroupA", Pid2),
      {ok, "GroupA", Pid2} = cpg:get_oldest_pid("GroupA"),
      {ok, "GroupA", Pid2} = cpg:get_newest_pid("GroupA"),
      erlang:exit(Pid1, kill),
      erlang:exit(Pid2, kill),
      erlang:exit(Pid3, kill),
      ok.
  
  callbacks_test() ->
  
negative.code:                                                         cpg_test_server1),
      {error, not_found} = supervisor_cpg:delete_child(SupViaName,
                                                       cpg_test_server1),
      ok = kill_pid(ChildPid3),
      timer:sleep(500),
      [{active, 1},
       {specs, 1},
       {supervisors, 0},
       {workers, 1}] = lists:sort(supervisor_cpg:count_children(SupViaName)),
      ok = kill_pid(SupPid),
      ok.
  
  pid_age_1_test() ->
  