Observable is not defined error while trying localForage.newObservable({})

[PraveenRL]

I'm working on [email protected] with [email protected] and localforage-observable@^2.1.1

Just following the same steps as in documentation, but getting error in localforage.newObservable(). Tried with different versions of localforage-observable also, but nothing works

import localForage from "localforage";
// OR based on your configuration:
// import * as localForage from "localforage";

import { extendPrototype } from "localforage-observable";

var localforage = extendPrototype(localForage);
localforage.ready().then(() => {
  // TypeScript will find `newObservable()` after the casting that `extendPrototype()` does
  var observable = localforage.newObservable();
});

Following error while running application:

Unhandled Promise rejection: Observable is not defined ; Zone: <root> ; Task: Promise.then ; Value: ReferenceError: Observable is not defined
    at newObservable.factory (localforage-observable.js:444:9)
    at LocalForage.newObservable (localforage-observable.js:431:40)