@classmethod
def connect(cls, controller_widget, control_name, control_instance):
    """ Connect a 'Controller' controller trait and a 'ControllerControlWidget'
        controller widget control.

        Parameters
        ----------
        cls: StrControlWidget (mandatory)
            a StrControlWidget control
        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
        """
    if not control_instance.connected:
        control_instance.controller_widget.connect()
        control_instance.connected = True
