docs: function _isFromCodeBlockInCodeMirror(cm, source, eventData) {
    // cursor in codeblock in markdown editor
    let fromCodeBlockInCodeMirror = source === 'markdown' && cm.getTokenAt(eventData.from).state.overlay.codeBlock;
    // or codeblock editor
    fromCodeBlockInCodeMirror = fromCodeBlockInCodeMirror || (source === 'codeblock');
    // but not from wysiwyg
    fromCodeBlockInCodeMirror = fromCodeBlockInCodeMirror && (source !== 'wysiwyg');
  
    return fromCodeBlockInCodeMirror;
  }