@Override
    public void toData(DataOutput out) throws IOException {
      out.writeInt(hashCode);
    }
Test the test method PartitionedRegion.getAllNodes Verify that it returns nodes after a value
has been placed into the PartitionedRegion.

@see PartitionedRegion#getAllNodes()
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/PartitionedRegionTestUtilsDUnitTest.java