{"ast_node_type":"other","tokens":[{"end":29,"kind":"keyword","start":0,"text":"opaque_ty_span:"}]}
        opaque_ty_span: Span,
        origin: hir::OpaqueTyOrigin<LocalDefId>,
        lower_item_bounds: impl FnOnce(&mut Self) -> &'hir [hir::GenericBound<'hir>],