message: Add id and parent_id in BuildTraceMe since they are not set in the constructor.
diff: @@ -546,11 +546,7 @@ DatasetBaseIterator::DatasetBaseIterator(const BaseParams& params)
  : params_(params) {
  params_.dataset->Ref();
  VLOG(2) << prefix() << " constructor";
  - traceme_metadata_ = strings::StrCat("id=", id_);
  - if (parent_) {
  - strings::StrAppend(&traceme_metadata_, ",parent_id=", parent_id_);
  - }
  - strings::StrAppend(&traceme_metadata_, ",shapes=");
  + strings::StrAppend(&traceme_metadata_, "shapes=");
  auto& shapes = output_shapes();
  for (int i = 0; i < shapes.size(); ++i) {
  if (i > 0) {
  @@ -574,7 +570,11 @@ DatasetBaseIterator::~DatasetBaseIterator() {
  }
  string DatasetBaseIterator::BuildTraceMeName() {
  - string result = strings::StrCat(params_.prefix, "#", traceme_metadata_);
  + string result =
  + strings::StrCat(params_.prefix, "#", traceme_metadata_, ",id=", id_);
  + if (parent_) {
  + strings::StrAppend(&result, ",parent_id=", parent_id_);
  + }
  TraceMeMetadata metadata = GetTraceMeMetadata();
  for (const auto& pair : metadata) {
  strings::StrAppend(&result, ",", pair.first, "=", pair.second);
  