src/vs/editor/contrib/zoneWidget/browser/zoneWidget.ts/ZoneWidget/constructor
class ZoneWidget:	constructor(editor: ICodeEditor, options: IOptions = {}) {
		this.editor = editor;
		this._positionMarkerId = this.editor.createDecorationsCollection();
		this.options = objects.deepClone(options);
		objects.mixin(this.options, defaultOptions, false);
		this.domNode = document.createElement('div');
		if (!this.options.isAccessible) {
			this.domNode.setAttribute('aria-hidden', 'true');
			this.domNode.setAttribute('role', 'presentation');
		}

		this._disposables.add(this.editor.onDidLayoutChange((info: EditorLayoutInfo) => {
			const width = this._getWidth(info);
			this.domNode.style.width = width + 'px';
			this.domNode.style.left = this._getLeft(info) + 'px';
			this._onWidth(width);
		}));
	}