Restarted the production of the app

libs/CLI11/examples/testEXE.cpp

@@ -0,0 +1,26 @@
+// Copyright (c) 2017-2022, University of Cincinnati, developed by Henry Schreiner
+// under NSF AWARD 1414736 and by the respective contributors.
+// All rights reserved.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code modified from https://github.com/CLIUtils/CLI11/issues/559
+
+#include <CLI/CLI.hpp>
+#include <iostream>
+#include <string>
+
+int main(int argc, const char *argv[]) {
+
+    int logLevel{0};
+    CLI::App app{"Test App"};
+
+    app.add_option("-v", logLevel, "level");
+
+    auto *subcom = app.add_subcommand("sub", "")->fallthrough();
+    subcom->preparse_callback([&app](size_t) { app.get_subcommand("sub")->add_option_group("group"); });
+
+    CLI11_PARSE(app, argc, argv);
+
+    std::cout << "level: " << logLevel << std::endl;
+}