syntax_data: {"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"iter_fields(args.as_coroutine().tupled_upvars_ty(),"}]}
source_snippet:             iter_fields(args.as_coroutine().tupled_upvars_ty(), tcx, typing_env, f);
context_before:         ty::Coroutine(_, args) => {
context_after:         }