syntax_data: {"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"args.as_coroutine_closure().tupled_upvars_ty(),"}]}
source_snippet:                     args.as_coroutine_closure().tupled_upvars_ty(),
context_before:                     tcx.lifetimes.re_erased,
context_after:                     args.as_coroutine_closure().coroutine_captures_by_ref_ty(),