Remove Widget

How to remove the Cyclone Slider 2 Widget from the “Widgets” page in the “Design” section?

With standard widgets you achieve this the following way:

function mmk_remove_widget_types() {
	unregister_widget( 'Cyclone_Slider_Widget' );
}
add_action( 'widgets_init', 'mmk_remove_widget_types' );

I figured out that the widget class is “Cyclone_Slider_Widget”, but this does not work.

https://wordpress.org/plugins/cyclone-slider-2/