public Collection<StreamEvent> findEvents(StateEvent matchingEvent, IndexedEventHolder indexedEventHolder) {

        if ((Boolean) expressionExecutor.execute(matchingEvent)) {
            return indexedEventHolder.getAllEvents();
        } else {
            return new HashSet<StreamEvent>();
        }
    }
Implementation of {@link CollectionExecutor} which handles non condition
modules/siddhi-core/src/main/java/io/siddhi/core/util/collection/executor/NonCollectionExecutor.java