-void add_schedule_options(po::options_description *positional) {
- positional->add_options()
- ("interval", "schedule interval");
+void add_schedule_options(po::options_description *positional,
+ bool mandatory) {
+ if (mandatory) {
+ positional->add_options()
+ ("interval", "schedule interval");
+ } else {
+ positional->add_options()
+ ("interval", po::value<std::string>()->default_value(""),
+ "schedule interval");
+ }