public static void serializeTo(Object obj, HeapDataOutputStream hdos) throws IOException {
    final int startBytes = hdos.size();
    final long start = startSerialization();
    DataSerializer.writeObject(obj, hdos);
    endSerialization(start, hdos.size() - startBytes);
  }
A blob is a serialized Object. This method serializes the object into the given
HeapDataOutputStream.
geode-core/src/main/java/org/apache/geode/internal/util/BlobHelper.java