syntax_data: {"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"sig_tys.output().skip_binder().fold_with(&mut"}]}
source_snippet:                     sig_tys.output().skip_binder().fold_with(&mut FoldEscapingRegions {
context_before:                 let coroutine_captures_by_ref_ty =
context_after:                         interner: cx,