title: Add UUID to spark dataset
body: <p>I am trying to add a UUID column to my dataset.</p>
  
  <pre><code>getDataset(Transaction.class)).withColumn("uniqueId", functions.lit(UUID.randomUUID().toString())).show(false);
  </code></pre>
  
  <p>But the result is all the rows have the same UUID. How can i make it unique?</p>
  
  <pre><code>+-----------------------------------+
  uniqueId                            |
  +----------------+-------+-----------
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  |1abdecf-8303-4a4e-8ad3-89c190957c3b|
  ----------+----------------+--------+
  </code></pre>