syntax_data: {"ast_node_type":"function","tokens":[{"end":70,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:                 fn try_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>(
context_before:             impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for $ty {
context_after:                     self,