public List<Object> execute(Function rebalanceFunction, Object[] functionArgs,
        DistributedMember dsMember) {
      return (List<Object>) ManagementUtils.executeFunction(rebalanceFunction,
          functionArgs, Collections.singleton(dsMember)).getResult();
    }
This class was introduced so that it can be mocked
to all executeRebalanceOnDS to be unit tested
geode-core/src/main/java/org/apache/geode/management/internal/operation/RebalanceOperationPerformer.java