private void checkSubnetExists(ServiceConfiguration configuration) throws Exception {
   DescribeSubnetsType describeSubnetsType =
       MessageHelper.createMessage(DescribeSubnetsType.class, info.getEffectiveUserId());
   describeSubnetsType.getFilterSet().add(Filter.filter("subnet-id", properties.getSubnetId()));
   DescribeSubnetsResponseType describeSubnetsResponseType =
       AsyncRequests.sendSync(configuration, describeSubnetsType);
   if (describeSubnetsResponseType.getSubnetSet() == null
       || describeSubnetsResponseType.getSubnetSet().getItem() == null
       || describeSubnetsResponseType.getSubnetSet().getItem().isEmpty()) {
     throw new ValidationErrorException("No such subnet with id '" + properties.getSubnetId());
   }
 }
 private boolean subnetExistsForDelete(ServiceConfiguration configuration) throws Exception {
   DescribeSubnetsType describeSubnetsType =
       MessageHelper.createMessage(DescribeSubnetsType.class, info.getEffectiveUserId());
   describeSubnetsType.getFilterSet().add(Filter.filter("subnet-id", properties.getSubnetId()));
   DescribeSubnetsResponseType describeSubnetsResponseType =
       AsyncRequests.sendSync(configuration, describeSubnetsType);
   if (describeSubnetsResponseType.getSubnetSet() == null
       || describeSubnetsResponseType.getSubnetSet().getItem() == null
       || describeSubnetsResponseType.getSubnetSet().getItem().isEmpty()) {
     return false;
   }
   return true;
 }