syntax_data: {"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"args.as_coroutine().yield_ty(),"}]}
source_snippet:             args.as_coroutine().yield_ty(),
context_before:             tcx.coroutine_kind(fn_def).unwrap(),
context_after:             args.as_coroutine().resume_ty(),