'**SUMMARY**
Checks the event queue and returns True if a quit event has been issued.
**RETURNS**
True on a quit event, False otherwise.
**EXAMPLE**
>>> disp = Display()
>>> cam = Camera()
>>> while not disp.isDone():
>>>   img = cam.getImage()
>>>   img.save(disp)'

def isDone(self):

    self.checkEvents()
    return self.done
