def METHOD_NAME(self, user_data_store):
    return forms.URLField(
        label="Server URL",
        help_text="Please insert the URL of the Piwigo server",
        required=False,
        max_length=1024,
        widget=forms.URLInput(attrs={"placeholder": "http://piwigo-server.com"}),
        initial=self.get_stored_value(user_data_store),
        validators=[self.validate_server_url])