I have created an editor via:
let editor = new Editorview( ... )
and everything works fine.
I try to set a theme using editor.setOption('theme', 'blackboard');
and it appears nothing happens.
From googling around, it appears this is the CodeMirror5 way of doing things.
In CodeMirror6, how do I set my theme to ‘blackboard’ (or any black-background theme?)