private void dumpOverlapProblems(Multimap<byte[], HbckRegionInfo> regions) {
    // we display this way because the last end key should be displayed as
    // well.
    for (byte[] k : regions.keySet()) {
      hbck.getErrors().print(Bytes.toStringBinary(k) + ":");
      for (HbckRegionInfo r : regions.get(k)) {
        hbck.getErrors()
          .print("[ " + r.toString() + ", " + Bytes.toStringBinary(r.getEndKey()) + "]");
      }
      hbck.getErrors().print("----");
    }
  }
This dumps data in a visually reasonable way for visual debugging
hbase-server/src/main/java/org/apache/hadoop/hbase/util/HbckTableInfo.java