static StochasticLoadBalancer buildStochasticLoadBalancer(BalancerClusterState cluster,
    Configuration conf) {
    StochasticLoadBalancer stochasticLoadBalancer =
      new StochasticLoadBalancer(new DummyMetricsStochasticBalancer());
    stochasticLoadBalancer.setClusterInfoProvider(new DummyClusterInfoProvider(conf));
    stochasticLoadBalancer.loadConf(conf);
    stochasticLoadBalancer.initCosts(cluster);
    return stochasticLoadBalancer;
  }
Partitions the given serverToRegions map by table The tables are derived from the RegionInfo
objects found in serverToRegions.
@param serverToRegions The map of servers to their assigned regions.
@return A map of tables to their server-to-region assignments.
hbase-balancer/src/test/java/org/apache/hadoop/hbase/master/balancer/CandidateGeneratorTestUtil.java