'See on_attribute_changed.'

def _check_for_updated_attributes(self):

    for (attribute, original_value) in self._recorded_attributes.iteritems():
        new_value = getattr(self, attribute)
        if (original_value != new_value):
            self.on_attribute_changed(attribute, original_value)
    self._record_attributes(self._recorded_attributes.keys())
