WorkManager.java

WorkManager.getInstance(context).enqueue(notificationWork);

//alternatively, we can use this form to determine what happens to the existing stack
// WorkManager.getInstance(context).beginUniqueWork(workTag, ExistingWorkPolicy.REPLACE, notificationWork);

//ExistingWorkPolicy.REPLACE - Cancel the existing sequence and replace it with the new one
//ExistingWorkPolicy.KEEP - Keep the existing sequence and ignore your new request
//ExistingWorkPolicy.APPEND - Append your new sequence to the existing one, 
                            //running the new sequence's first task after the existing sequence's last task finishes