In most code examples given (both in GitHub & official docs) where a sleep is needed, then Thread.sleep(x) is used. For example:

• https://github.com/GoogleCloudPlatform/google-cloud-java/tree/master/google-cloud-bigquery
• https://cloud.google.com/bigquery/querying-data

For better readability/clarity, then it may be prudent to consider using the TimeUnit class instead. Yes, it's all the same as it calls Thread.sleep(x) under the hood, but consider the following as an example:

Thread.sleep(180000) vs. TimeUnit.MINUTES.sleep(3)

More info: http://stackoverflow.com/questions/9587673/thread-sleep-vs-timeunit-seconds-sleep