}
@Override
protected String getLastUpdateTime() throws Exception{
GetCategoriesCall api = new GetCategoriesCall(apiContext);
GetCategoriesRequestType req = new GetCategoriesRequestType();
//we only need 'UpdateTime' field
req.setOutputSelector(new String[]{"UpdateTime"});
api.execute(req);
GetCategoriesResponseType resp = (GetCategoriesResponseType) api.execute(req);
Date date = resp.getUpdateTime().getTime();
SimpleDateFormat df = new SimpleDateFormat("yyyy_MM_dd_hh_mm_ss");
String time = df.format(date);