private boolean routeTableExistsForDelete(ServiceConfiguration configuration) throws Exception {
   DescribeRouteTablesType describeRouteTablesType =
       MessageHelper.createMessage(DescribeRouteTablesType.class, info.getEffectiveUserId());
   describeRouteTablesType
       .getFilterSet()
       .add(Filter.filter("route-table-id", properties.getRouteTableId()));
   DescribeRouteTablesResponseType describeRouteTablesResponseType =
       AsyncRequests.sendSync(configuration, describeRouteTablesType);
   if (describeRouteTablesResponseType.getRouteTableSet() == null
       || describeRouteTablesResponseType.getRouteTableSet().getItem() == null
       || describeRouteTablesResponseType.getRouteTableSet().getItem().isEmpty()) {
     return false;
   }
   return true;
 }
 private void checkRouteTableExists(ServiceConfiguration configuration) throws Exception {
   DescribeRouteTablesType describeRouteTablesType =
       MessageHelper.createMessage(DescribeRouteTablesType.class, info.getEffectiveUserId());
   describeRouteTablesType
       .getFilterSet()
       .add(Filter.filter("route-table-id", properties.getRouteTableId()));
   DescribeRouteTablesResponseType describeRouteTablesResponseType =
       AsyncRequests.sendSync(configuration, describeRouteTablesType);
   if (describeRouteTablesResponseType.getRouteTableSet() == null
       || describeRouteTablesResponseType.getRouteTableSet().getItem() == null
       || describeRouteTablesResponseType.getRouteTableSet().getItem().isEmpty()) {
     throw new ValidationErrorException(
         "No such route table with id '" + properties.getRouteTableId());
   }
 }