{"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"OpaqueTypeLifetimeCollector"}]}
        OpaqueTypeLifetimeCollector { tcx, root_def_id: item_def_id.to_def_id(), variances };
    let mut collector =
    let id_args = ty::GenericArgs::identity_for_item(tcx, item_def_id);