def waitForValueToChange(self, timeout=<NUM_LIT:10>):
<EOL>callback = AXCallbacks.returnElemCallback<EOL>retelem = None<EOL>return self.waitFor(timeout, '<STR_LIT>', callback=callback,<EOL>args=(retelem,))<EOL>
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