syntax_data: {"ast_node_type":"other","tokens":[{"end":49,"kind":"keyword","start":0,"text":")"}]}
source_snippet:     ) -> Result<Option<ty::TraitRef<'tcx>>, ()> {
context_before:         trait_bound: ty::PolyTraitRef<'tcx>,
context_after:         debug_assert!(!placeholder_trait_ref.has_escaping_bound_vars());