code: def waitForValueToChange(self, timeout=10):
          
          # Want to identify that the element whose value changes matches this
          # object's.  Unique identifiers considered include role and position
          # This seems to work best if you set the notification at the application
          # level
          callback = AXCallbacks.returnElemCallback
          retelem = None
          return self.waitFor(timeout, 'AXValueChanged', callback=callback,
                              args=(retelem,))
docs: Convenience method to wait for value attribute of given element to
          change.
  
          Some types of elements (e.g. menu items) have their titles change,
          so this will not work for those.  This seems to work best if you set
          the notification at the application level.
  
          Returns: Element or None