DataProvider for combobox without two step fetch and count

I would like to use ComboBox to return dynamic list of items depending on what typed in. There is no back-end call, but list is dynamic. I’m currently using DataProvider.fromFilteringCallbacks. However, using DataProvider, I must implementation both fetch and count which executes my logic twice. Are there alternative to DataProvider.fromFilteringCallbacks when implementing this kind of situation? Thanks

    List<String> items = Arrays.asList("Foo", "Bar", "Baz");
    ComboBox<String> cb = new ComboBox<>();
    cb.setItems((Query<String, String> query)
                .filter(i -> i.startsWith(query.getFilter().get()))

Thanks. I was going through API signatures, but missed this one.