public void addPolicyFileUrl(String url){
  if (policyFileUrls == null) {
    policyFileUrls=new ArrayList<String>();
  }
  policyFileUrls.add(url == null ? "" : url);
}

public void addPolicyFileUrl ( String url ) { if ( policyFileUrls == null ) { policyFileUrls = new ArrayList < String > ( ) ; } policyFileUrls . add ( url == null ? "" : url ) ; }
add a policy file to support the associated entry in the rsl url list . policy file entries my be empty , but must be specified .
