@classmethod
def update_controller_widget(cls, controller_widget, control_name,
    control_instance):
    """ Update one element of the controller control widget.

        At the end the controller control widget user editable parameter with the
        name 'control_name' will match the controller trait value with the same
        name.

        Parameters
        ----------
        controller_widget: ControllerWidget (mandatory)
            a controller widget that contains the controller we want to update
        control_name: str(mandatory)
            the name of the controller widget control we want to synchronize
            with the controller
        control_instance: QFrame (mandatory)
            the instance of the controller widget control we want to
            synchronize with the controller
        """
    control_instance.controller_widget.update_controller_widget()
