I create MyEvent:

import EmitterMixin from '@ckeditor/ckeditor5-utils/src/emittermixin';
import mix from '@ckeditor/ckeditor5-utils/src/mix';

export default class MyEvent {

}

mix( MyEvent, EmitterMixin );

In my custom plugin I wrote:

(new MyEvent).fire('my-super-event', {   
  ...someData,
})

Subscribe to my event:

editor.on('my-super-event', event => {
  console.log('My event: ', event);
});

But nothing happens, why?