public MapStoreConfig setWriteBatchSize(int writeBatchSize) {
        if (writeBatchSize < 1) {
            throw new IllegalArgumentException("Write batch size must be at least 1");
        }
        this.writeBatchSize = writeBatchSize;
        return this;
    }
@Test(expected = IllegalArgumentException.class)
    public void setWriteBatchSize_whenLessThanOne() {
        MapStoreConfig cfg = new MapStoreConfig().setWriteBatchSize(-15);
    }