syntax_data: {"ast_node_type":"function","tokens":[{"end":57,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
context_before: impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for WfPredicates<'a, 'tcx> {
context_after:         debug!("wf bounds for t={:?} t.kind={:#?}", t, t.kind());