anchor.diff:      Pattern = #opener{pid=Pid, _='_'},
       case ets:match_object(?OPENING, Pattern) of
           [#opener{key=Key, clients=Clients}] ->
  -            [gen_server:reply(C, {error, Reason}) || C <- Clients],
  +            _ = [gen_server:reply(C, {error, Reason}) || C <- Clients],
               ets:delete(?OPENING, Key),
               {noreply, St};
           [] ->
  
positive.code: 
  respond(Key, Resp) ->
      [#opener{clients=Clients}] = ets:lookup(?OPENING, Key),
      [gen_server:reply(C, Resp) || C <- Clients],
      ets:delete(?OPENING, Key).
  
negative.code:     {ok, St}.
  
  
  -spec open_ddoc({dbname(), validation_funs | docid()}) -> no_return().
  open_ddoc({DbName, validation_funs}=Key) ->
      {ok, DDocs} = fabric:design_docs(mem3:dbname(DbName)),
      Funs = lists:flatmap(fun(DDoc) ->
  