{"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"self.check_nested_types_are_exportable(sig.output(),"}]}
            self.check_nested_types_are_exportable(sig.output(), ret_hir.span);
        if let hir::FnRetTy::Return(ret_hir) = decl.output {
        }