syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"TraitPredicate"}]}
source_snippet:         TraitPredicate { trait_ref: from, polarity: PredicatePolarity::Positive }
context_before:     fn upcast_from(from: TraitRef<I>, _tcx: I) -> Self {
context_after:     }