called when we want to queue a timed event onto the model's event queue
this also tracks all the pending events so that if they fire or get aborted
we are notified, and it permits us to abort when a clear is called
called when we want to queue a timed event onto the model's event queue
this also tracks all the pending events so that if they fire or get aborted
we are notified, and it permits us to abort when a clear is called