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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _transientSchedule(self, when, now):
 """ If this service's store is attached to its parent, ask the parent to schedule this substore to tick at the given time. @param when: The time at which to tick. @type when: L{epsilon.extime.Time} @param now: Present for signature compatibility with L{_SiteScheduler._transientSchedule}, but ignored otherwise. """

        if self.store.parent is not None:
            subStore = self.store.parent.getItemByID(self.store.idInParent)
            hook = self.store.parent.findOrCreate(
                _SubSchedulerParentHook,
                subStore=subStore)
            hook._schedule(when)