docs: Set<String> removeServiceIfTraceId(String lowTraceId) {
        Set<String> result = new LinkedHashSet<>();
        for (Map.Entry<String, Collection<String>> entry : delegate.entrySet()) {
          Collection<String> lowTraceIds = entry.getValue();
          if (lowTraceIds.remove(lowTraceId) && lowTraceIds.isEmpty()) {
            result.add(entry.getKey());
          }
        }
        delegate.keySet().removeAll(result);
        return result;
      }