/**
  * Create policy set using the added policy ot policy sets
  *
  * @param policySetDTO policy set element
  * @return String object of the XACML policy Set
  * @throws EntitlementPolicyCreationException throws
  */
 public String createPolicySet(PolicySetDTO policySetDTO)
     throws EntitlementPolicyCreationException {
   try {
     Document doc = createNewDocument();
     if (doc != null) {
       doc.appendChild(PolicyCreatorUtil.createPolicySetElement(policySetDTO, doc));
       StringBuilder policySet = new StringBuilder(PolicyCreatorUtil.getStringFromDocument(doc));
       if (policySetDTO.getPolicies() != null) {
         for (String policy : policySetDTO.getPolicies()) {
           policySet.insert(policySet.indexOf(">") + 1, policy);
         }
       }
       return policySet.toString();
     }
   } catch (EntitlementPolicyCreationException e) {
     throw new EntitlementPolicyCreationException("Error While Creating Policy Set", e);
   }
   return null;
 }