{"ast_node_type":"other","tokens":[{"end":59,"kind":"keyword","start":0,"text":"|"}]}
                    | hir::CoroutineKind::Coroutine(_) => {
                    hir::CoroutineKind::Desugared(hir::CoroutineDesugaring::Gen, _)
                        let yield_ty = self.next_ty_var(expr_span);