How to retrieve firewall rules of an org network

Hi,

I am using vCloud SDK 1.5 for java,

I want to retrieve firewall rules of an organisation.

There are some classes in SDK related to firewall ( FirewallServiceType,FirewallRuleType,FirewallRuleProtocols etc)

I am not sure how to use these classes to get firewall details , There is no sample code available in "SamplesSDK",

I tried below code....but as expected it giving NULL value

FirewallServiceType firewallServiceType = new FirewallServiceType();
     List<FirewallRuleType> firewallRules = firewallServiceType.getFirewallRule();

for (Iterator iterator = firewallRules.iterator(); iterator.hasNext();) {
        FirewallRuleType firewallRuleType = (FirewallRuleType) iterator
                    .next();
         System.out.println("Firewall Policy Desc : "+firewallRuleType.getDescription() );
        }

Pls help me to get firewall rules.