syntax_data: {"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"impl<I:"}]}
source_snippet: impl<I: Interner> UpcastFrom<I, TraitRef<I>> for TraitPredicate<I> {
context_after:     fn upcast_from(from: TraitRef<I>, _tcx: I) -> Self {