src/vs/workbench/contrib/notebook/browser/contrib/editorStatusBar/editorStatusBar.ts/ActiveCellStatus/constructor
class ActiveCellStatus:	constructor(
		@IEditorService private readonly _editorService: IEditorService,
		@IStatusbarService private readonly _statusbarService: IStatusbarService,
	) {
		super();
		this._register(this._editorService.onDidActiveEditorChange(() => this._update()));
	}