OpenLayers 6/7: Toggle feature visibility

Question

How can I toggle the visibility of a feature in OpenLayers?

There are similar posts, which answers suggests to change the feature style. However, I have a scenario where the style is unknown, so I can't assign it back when I want to show the feature again. Similar posts:

• OpenLayers toggle feature visibility (Show/hide)
• https://gis.stackexchange.com/questions/270387/show-hide-features-on-layer-in-openlayers

Here is a JSFiddle to make demonstration easier: https://jsfiddle.net/aejko5n6/

It would be great if something like this was possible:

function toggleVisiblity() {
  console.log('button click!');
  
  if(lineFeature.get('hidden')) {
    lineFeature.unset('hidden');
  } else {
    lineFeature.set('hidden', true);
  }
  
  vector.changed();
}