diff --git a/js/tree.js b/js/tree.js
index 1a2ddfe..86cf15e 100644
--- a/js/tree.js
+++ b/js/tree.js
@@ -57,6 +57,7 @@ export const Menu = (props) => {
   /** @type {React.MutableRefObject<null|Toggler>} */
   const refCollapser = React.useRef(null);
 
+  console.log("render...");
   React.useEffect(() => {
     refElement.current &&
       (refCollapser.current = Collapser(refElement.current));
@@ -89,6 +90,8 @@ export const Menu = (props) => {
 /** @typedef {(inElement:HTMLElement)=>Toggler} Collapse */
 /** @type Collapse */
 const Collapser = (inElement) => {
+  console.log("collapser initialized");
+
   /** @type UserDone */
   let userDone = () => {};
   let userMode = false;
@@ -109,6 +112,8 @@ const Collapser = (inElement) => {
 
   /** @type Toggler */
   const show = (inOpen, inMs, inDone) => {
+    console.log("collapser invoked");
+
     cancelAnimationFrame(frameRequest);
     if ((!inOpen && !inMs) && !inDone) {
       inElement.removeEventListener("transitionend", done);