/**
* A sub system represents a part of a system that required a
* number of services and provides a number of services.
/**
* A sub system represents a part of a system that required a
* number of services and provides a number of services.
* subsystems that are required by this subsystem.
* @return Services that are running in the subsystem.
*/
* subsystems that are required by this subsystem.
* @return Services that are running in the subsystem.
*/