@Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("BatchEventData{");
        for (QueryCacheEventData event : events) {
            stringBuilder.append(event);
        }
        stringBuilder.append("}");
        return stringBuilder.toString();
    }
@Test
    public void testToString() {
        assertContains(batchEventData.toString(), "BatchEventData");
    }