{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
    let well_known = db.lang_attr(trait_.into()).and_then(well_known_trait_from_lang_item);
    let trait_datum_bound = rust_ir::TraitDatumBound { where_clauses };
    let trait_datum = TraitDatum {