public FSProtos.Reference convert() {
    FSProtos.Reference.Builder builder = FSProtos.Reference.newBuilder();
    builder.setRange(isTopFileRegion(getFileRegion())
      ? FSProtos.Reference.Range.TOP
      : FSProtos.Reference.Range.BOTTOM);
    builder.setSplitkey(UnsafeByteOperations.unsafeWrap(getSplitKey()));
    return builder.build();
  }
@deprecated Writables are going away. Use the pb serialization methods instead. Remove in a
            release after 0.96 goes out. This is here only to migrate old Reference files
            written with Writables before 0.96.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/Reference.java