anchor.diff:              repeat_until_any_fail.
   -type ct_test_repeat() :: integer() |
               forever.
  --type ct_groups_def() :: {ct_groupname(), ct_group_props(), [
  +-type ct_group_def() :: {ct_groupname(), ct_group_props(), [
                   ct_testname() |
  -                ct_groups_def() |
  +                ct_group_def() |
                   {group, ct_groupname()} |
                   ct_testcase_ref()
               ]}.
  
positive.code: -type ct_group_ref() :: {group, ct_groupname()} |
              {group, ct_groupname(), ct_group_props_ref()} |
              {group, ct_groupname(), ct_group_props_ref(), ct_subgroups_def()}.
  -type ct_testcase_ref() :: {testcase, ct_testname(), ct_testcase_repeat_props()}.
  -type ct_testcase_repeat_props() :: {repeat, ct_test_repeat()} |
              {repeat_until_ok, ct_test_repeat()} |
              {repeat_until_fail, ct_test_repeat()}.
  -type ct_info() :: {timetrap, ct_info_timetrap()} |
  
negative.code:               ct_groupname/0,
                ct_config/0,
                ct_status/0,
                ct_group_def/0,
                ct_test_def/0,
                ct_info/0
               ]).
  
  