Release. Bump version number

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@barchart/common-js",
-  "version": "4.9.0",
+  "version": "4.9.1",
   "description": "Library of common JavaScript utilities",
   "author": {
     "name": "Bryan Ingle",

test/SpecRunner.js

@@ -27665,7 +27665,19 @@ module.exports = (() => {
         let token;
         const schedulePromise = promise.build((resolveCallback, rejectCallback) => {
           const wrappedAction = () => {
-            delete this._timeoutBindings[token];
+            const disposable = this._timeoutBindings[token]; // 2021/05/18, BRI. Invoking dispose cases the clearTimeout function to run.
+            // Running clearTimeout should not be necessary because the timer has elapsed
+            // and the callback is being invoked. However, failing to call clearTimeout in
+            // a Node.js environment (after version 10) leads to a memory leak. Notice that
+            // this function has a reference to the Scheduler instance (via closure). In my
+            // view, this is breaking change between versions 10 and 12 of Node.js. I have
+            // been unable to locate any documentation regarding this change; however, a changes
+            // to did occur (which becomes obvious when inspecting the data structure returned by
+            // the setTimeout function).
+
+            if (disposable) {
+              disposable.dispose();
+            }
 
             try {
               resolveCallback(actionToSchedule());