OPT_HOOK(opt_test_hook, "preval", OPT_HOOK_BEFORE_VALUE),
OPT_HOOK(opt_test_hook, "postval", OPT_HOOK_AFTER_VALUE),
OPT_BOOL('H', "show-hooks", show_hooks, 0, "\tDemonstrate the hooks."),
OPT_HOOK(opt_test_hook, "preval", OPT_HOOK_BEFORE_VALUE),
OPT_HOOK(opt_test_hook, "postval", OPT_HOOK_AFTER_VALUE),
OPT_BOOL('H', "show-hooks", show_hooks, 0, "\tDemonstrate the hooks."),