{"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"let"}]}
    let id_args = ty::GenericArgs::identity_for_item(tcx, item_def_id);
        OpaqueTypeLifetimeCollector { tcx, root_def_id: item_def_id.to_def_id(), variances };
    for (pred, _) in tcx.explicit_item_bounds(item_def_id).iter_instantiated_copied(tcx, id_args) {