syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"debug!(?impl_def_id,"}]}
source_snippet:         debug!(?impl_def_id, ?args, ?recursion_depth, "vtable_impl");
context_before:     ) -> ImplSourceUserDefinedData<'tcx, PredicateObligation<'tcx>> {