anchor.diff:  
   %% Send an event at connection establishment failure.
   closed({shutdown, {close, _TPid, Reason}},
  -       #peer{op_state = ?STATE_DOWN,
  +       #peer{op_state = {?STATE_DOWN, _},
                ref = Ref,
                type = Type,
                options = Opts},
  
positive.code:                          op_state = OS,
                           started = T,
                           conn = TPid}) ->
      dict:append(Ref,
                  [{type, Type},
                   {options, Opts},
                   {watchdog, {Pid, T, OS}}
                   | info_conn(ConnT, TPid)],
                  Acc).
  
  info_conn(ConnT, TPid) ->
      info_conn(ets:lookup(ConnT, TPid)).
  
  info_conn([#conn{pid = Pid, apps = SApps, caps = Caps, started = T}]) ->
      [{peer, {Pid, T}},
  
negative.code: 
  fetch(Tid, Key) ->
      [T] = ets:lookup(Tid, Key),
      case T of
          #peer{op_state = ?STATE_UP} = P ->
              P#peer{op_state = {?STATE_UP, ?WD_OKAY}};
          #peer{op_state = ?STATE_DOWN} = P ->
              P#peer{op_state = {?STATE_DOWN, ?WD_DOWN}};
          _ ->
              T
      end.
  
  %%% ---------------------------------------------------------------------------
  %%% # connection_up/3
  