@Override
  public Integer getUserId() {
    return (proxiedUserDetails instanceof AmbariUserDetails) ? ((AmbariUserDetails) proxiedUserDetails).getUserId() : null;
  }
Details about the proxy user that was authenticated.
<p>
This user that authenticated wth Ambari but specified a doAs or proxied user to be used as the acting user for operations.
ambari-server/src/main/java/org/apache/ambari/server/security/authentication/AmbariProxiedUserDetailsImpl.java