the note section in asynchronous code says:
Note: As a real-world example of async(), you can check out this part of the Now in Android app. In the SyncWorker class, the call to sync() returns a boolean if the sync to a particular backend was successful. If any of the sync operations failed, then the app needs to perform a retry.
However, the link to SyncWorker.kt shows a file not found page on GitHub from the now in android app, so I can't actually see an example of a deferred object being returned from a async() call and its boolean value being used via await to wait for the coroutine function to return its value to the deferred object.