src/vs/editor/browser/editorDom.ts/EditorPointerEventFactory/onPointerLeave
class EditorPointerEventFactory:	public onPointerLeave(target: HTMLElement, callback: (e: EditorMouseEvent) => void): IDisposable {
		return dom.addDisposableNonBubblingPointerOutListener(target, (e: MouseEvent) => {
			callback(this._create(e));
		});
	}