private void doPuts(String regionName) {
    Region<Number, String> region = getCache().getRegion(regionName);
    region.put(1, "A");
    region.put(2, "A");
    region.put(3, "A");
    region.put(4, "A");
    region.put(5, "A");
    region.put(6, "A");
  }
NOTE: do not replace createPartitionedRegionRunnable with lambda
because ResourceObserverAdapter is NOT serializable
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/control/RebalanceOperationDistributedTest.java