@Test
  public void testVerifyCacheAwareSkewnessCostFunctionDisabled() {
    conf.setFloat(
      CacheAwareLoadBalancer.CacheAwareRegionSkewnessCostFunction.REGION_COUNT_SKEW_COST_KEY, 0.0f);

    CacheAwareLoadBalancer lb = new CacheAwareLoadBalancer();
    lb.loadConf(conf);

    assertFalse(Arrays.asList(lb.getCostFunctionNames())
      .contains(CacheAwareLoadBalancer.CacheAwareRegionSkewnessCostFunction.class.getSimpleName()));
  }
Data set to testCacheCost: [test][0][0] = mapping of server to number of regions it hosts
[test][region + 1][0] = server that region is hosted on [test][region + 1][server + 1] = size
of region cached on server
hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestCacheAwareLoadBalancerCostFunctions.java