Currently, I\'m using WorkManager 1.0.0-alpha02.
def work_version = \"1.0.0-alpha02\" implementation \"android.arch.work:work-runtime:$work_version\" // use -ktx
The answer from @ianhanniballake is of course helpful and correct, but I thought I'd point out that (with a fast-evolving API) there is a new enqueueUniqueWork() method so I guess the OP could now use:
workManager.enqueueUniqueWork( SyncWorker.TAG, ExistingWorkPolicy.REPLACE, oneTimeWorkRequest );