Return true if the director wishes to be scheduled for another iteration. This method is called by the container of this director to see whether the director wishes to execute anymore. It should
not, in general, call postfire() on the contained actors.
In this base class, return the false if stop() has been called since preinitialize(), and true otherwise. Derived classes that override this method need to respect this semantics. The protected variable _stopRequested indicates whether stop() has been called.
@return True to continue execution, and false otherwise.
@exception IllegalActionException Not thrown in this base class.