Stream is empty then fetchFromBackEnd from AbstractBackEndDataProvider goes

Vaadin 6 / 7 / 8 Framework Data Binding
1

Hi,
I have a GridPagedDataProvider that extends AbstractBackEndDataProvider in which I implement

    @Override
    protected Stream<T> fetchFromBackEnd(Query<T, F> query) {
        Collection<T> result = Collections.emptyList();
        result = crudListener.findAll();
        return result.stream();
    }

If the result is empty, then this function is called continuosly. I am using Vaadin 8.0.5

Any ideas?