private HRegion initHRegion(byte[] tableName, String callingMethod, Configuration conf,
    String family) throws IOException {
    return initHRegion(tableName, callingMethod, conf, family, null);
  }
Callers must afterward call {@link HBaseTestingUtil#closeRegionAndWAL(HRegion)}
@return created and initialized region.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestBlocksRead.java