src/vs/editor/contrib/gotoSymbol/browser/peek/referencesController.ts/withController
function withController(accessor: ServicesAccessor, fn: (controller: ReferencesController) => void): void {
	const outerEditor = getOuterEditor(accessor);
	if (!outerEditor) {
		return;
	}
	const controller = ReferencesController.get(outerEditor);
	if (controller) {
		fn(controller);
	}
}