@SuppressWarnings("unchecked")
  private static Class<? extends HRegionServer>
    getRegionServerImplementation(final Configuration conf) {
    return (Class<? extends HRegionServer>) conf.getClass(HConstants.REGION_SERVER_IMPL,
      HRegionServer.class);
  }
Constructor.
@param conf            Configuration to use. Post construction has the active master address.
@param noMasters       Count of masters to start.
@param noRegionServers Count of regionservers to start.
hbase-server/src/main/java/org/apache/hadoop/hbase/LocalHBaseCluster.java