{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
        let normalize_cause = traits::ObligationCause::misc(span, impl_def_id);
    for (clause, span) in tcx.predicates_of(impl_def_id).instantiate(tcx, fresh_impl_args) {
        let pred = ocx.normalize(&normalize_cause, adt_env, clause);