_metadata_generating_visitor{lttng::make_unique<ls::tsdl::trace_class_visitor>(abi,
[this](const std::string& fragment) {
_append_metadata_fragment(fragment);
_metadata_generating_visitor{lttng::make_unique<ls::tsdl::trace_class_visitor>(abi,
[this](const std::string& fragment) {
_append_metadata_fragment(fragment);