syntax_data: {"ast_node_type":"other","tokens":[{"end":88,"kind":"keyword","start":0,"text":"impl<'tcx>"}]}
source_snippet: impl<'tcx> Relate<TyCtxt<'tcx>> for &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>> {
context_after:     fn relate<R: TypeRelation<TyCtxt<'tcx>>>(