def _update_proxy(self, change):
        """ Update the proxy widget when the Widget data
        changes.
        """
        #: Try default handler
        if change['type'] == 'update' and self.proxy_is_active:
            handler = getattr(self.proxy, 'set_' + change['name'], None)
            if handler is not None:
                handler(change['value'])
            else:
                self.proxy.set_attribute(change['name'], change['value'])
            self._notify_modified(change)
Update the proxy widget when the Widget data
        changes.