@Override
  public Properties getDistributedSystemProperties() {
    Properties props = super.getDistributedSystemProperties();
    props.setProperty(OFF_HEAP_MEMORY_SIZE, "10m");
    return props;
  }
Tests Distributed Ack Region with OffHeap memory.

@since Geode 1.0
geode-core/src/distributedTest/java/org/apache/geode/cache30/DistributedAckRegionOffHeapDUnitTest.java