@Override
  protected AbstractKerberosDescriptor getDescriptor(Type type, String name) {
    if (Type.SERVICE == type) {
      return getService(name);
    } else {
      return super.getDescriptor(type, name);
    }
  }
Gets the requested AbstractKerberosDescriptor implementation using a type name and a relevant
descriptor name.
<p/>
This implementation handles service descriptors and delegates to the AbstractKerberosDescriptor
implementation to handle component and identity types.

@param type a String indicating the type of the requested descriptor
@param name a String indicating the name of the requested descriptor
@return a AbstractKerberosDescriptor representing the requested descriptor or null if not found
ambari-server/src/main/java/org/apache/ambari/server/state/kerberos/KerberosDescriptor.java