{"ast_node_type":"impl","tokens":[{"end":85,"kind":"keyword","start":0,"text":"lower_item_bounds:"}]}
        lower_item_bounds: impl FnOnce(&mut Self) -> &'hir [hir::GenericBound<'hir>],
        opaque_ty_span: Span,
    ) -> hir::TyKind<'hir> {