syntax_data: {"ast_node_type":"variable","tokens":[{"end":44,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let trait_ref = predicate.trait_ref;
context_before:         let predicate = self.infcx.enter_forall_and_leak_universe(obligation.predicate);
context_after:         let trait_def_id = trait_ref.def_id;