How to query id-s of a vapp though the query service

Hi

I would like to retrieve the id-s of the vapps (based on a filter), but i get "Property id is invalid for query vApp."

Set<QueryVAppField> fields = Sets.newHashSet();
fields.add(QueryVAppField.ID);
Expression expression = ...
Filter filter = new Filter(expression);
QueryParams<QueryVAppField> queryParams = new QueryParams<QueryVAppField>();
queryParams.setFilter(filter);
queryParams.setFields(fields);
RecordResult<QueryResultVAppRecordType> records = cloud.getConnector().getQueryService().queryvAppIdRecords(queryParams);

<Error xmlns="http://www.vmware.com/vcloud/v1.5" minorErrorCode="BAD_REQUEST" message="Property id is invalid for query vApp." majorErrorCode="400" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.vmware.com/vcloud/v1.5http://172.16.1.20/api/v1.5/schema/master.xsd"></Error>

Thanks

Denes