src/vs/base/browser/ui/hover/hoverWidget.ts/HoverWidget/constructor
class HoverWidget:	constructor() {
		super();

		this.containerDomNode = document.createElement('div');
		this.containerDomNode.className = 'monaco-hover';
		this.containerDomNode.tabIndex = 0;
		this.containerDomNode.setAttribute('role', 'tooltip');

		this.contentsDomNode = document.createElement('div');
		this.contentsDomNode.className = 'monaco-hover-content';

		this.scrollbar = this._register(new DomScrollableElement(this.contentsDomNode, {
			consumeMouseWheelIfScrollbarIsNeeded: true
		}));
		this.containerDomNode.appendChild(this.scrollbar.getDomNode());
	}