The Stoppable type exposes the following members.
Throws if the current thread isn't holding any type of lock.
Throws if the control is already shutting down.
Throws if the current thread doesn't hold a write lock.
Triggered when the ShutdownToken is canceled.
Dispose the object.
Enter the lock in read mode.
Enter the lock in write mode.
Exit the currently held read lock.
Exit the currently held write lock.
Triggered after all shutdown operations have completed.
Starts the shutdown process, if it hasn't already begun.