From fc5683d22de15bf5e077899ea76434287aae220c Mon Sep 17 00:00:00 2001
From: Sam Reid <reids@colorado.edu>
Date: Sun, 13 Feb 2022 11:46:33 -0700
Subject: [PATCH] Convert AccordionBox to TypeScript, see
 https://github.com/phetsims/sun/issues/738

---
 js/PhetioObject.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/PhetioObject.ts b/js/PhetioObject.ts
index bf1caa4f..d7e32d29 100644
--- a/js/PhetioObject.ts
+++ b/js/PhetioObject.ts
@@ -392,7 +392,7 @@ class PhetioObject {
    * @param event - the name of the event
    * @param [options]
    */
-  phetioStartEvent( event: string, options: any ): void {
+  phetioStartEvent( event: string, options?: any ): void {
     if ( PHET_IO_ENABLED && this.isPhetioInstrumented() ) {
 
       // only one or the other can be provided