{"ast_node_type":"variable","tokens":[{"end":62,"kind":"keyword","start":0,"text":"let"}]}
    let trait_self = match generic_params.trait_self_param() {
    let generic_params = db.generic_params(trait_ref.hir_trait_id().into());
        Some(p) => TypeOrConstParamId { parent: trait_ref.hir_trait_id().into(), local_id: p },