title: How to know the group name of a spark user from a spark application
body: <p>I want to know the group name to which a particular spark user belongs from a spark application program. Currently, I can retrieve the name of a spark user using <code>spark.sparkContext.sparkUser</code></p>
  
  <p>Is there any API/method which will give me group name to which this spark user belongs.
  I know there is a linux command <code>id &lt;user-name&gt;</code> but my requirement is to get the group name in a programmatic manner.</p>