src/vs/workbench/services/hover/browser/hoverWidget.ts/CompositeMouseTracker/constructor
class CompositeMouseTracker:	constructor(
		private _elements: HTMLElement[]
	) {
		super();
		this._elements.forEach(n => this.onmouseover(n, () => this._onTargetMouseOver()));
		this._elements.forEach(n => this.onmouseleave(n, () => this._onTargetMouseLeave()));
	}