// Do not add the result in the datapool yet, but rather add this object on success
DataSource ds = poolToSearch.provide(id,dscId,realOption,false);
if (ds==null) return null;
if (ds instanceof EmptyDataSource){
DefaultEmptyDataSource emptyDs = new DefaultEmptyDataSource(id, marker + dscId, optionalInformation);
EmptyDataSourcePool.global.addEmptyDaSource(id, emptyDs);
return emptyDs;
}
if (ds instanceof BufferedDataSource) ds = ((BufferedDataSource)ds).dataSource;