syntax_data: {"ast_node_type":"variable","tokens":[{"end":72,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let transmute_trait = obligation.predicate.def_id();
context_before:                 Condition::Transmutable { src, dst } => {
context_after:                     let assume = obligation.predicate.skip_binder().trait_ref.args.const_at(2);