syntax_data: {"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"parent_trait_pred:"}]}
source_snippet:         parent_trait_pred: ty::Binder<'tcx, ty::TraitPredicate<'tcx>>,
context_before:         args: GenericArgsRef<'tcx>, // for impl or trait
context_after:     ) -> PredicateObligations<'tcx> {