@Override
  public boolean isContainer() {
    return true;
  }
Test this AbstractKerberosDescriptor to see if it is a container.
<p/>
This implementation always returns true since it implements a descriptor container.

@return true if this AbstractKerberosDescriptor is a container, false otherwise
ambari-server/src/main/java/org/apache/ambari/server/state/kerberos/AbstractKerberosDescriptorContainer.java