syntax_data: {"ast_node_type":"other","tokens":[{"end":51,"kind":"keyword","start":0,"text":"from.map_bound(|trait_ref|"}]}
source_snippet:         from.map_bound(|trait_ref| TraitPredicate {
context_before:     fn upcast_from(from: ty::Binder<'tcx, TraitRef<'tcx>>, _tcx: TyCtxt<'tcx>) -> Self {
context_after:             trait_ref,