The [API]
(https://vaadin.com/api/platform/14.1.16/com/vaadin/flow/data/provider/Query.html#Query-F-) doc stated:
filter - back end filter of a suitable type for the data provider; can be null
Can somebody give an example ? I always use it in this way:
dataCombo.getDataProvider().fetch(new Query<>()).findFirst().... with an “empty” query.