code: private int getSerializationSize(final Object obj) {
  		try {
  			ByteArrayOutputStream bos = new ByteArrayOutputStream();
  			ObjectOutputStream oos = new ObjectOutputStream(bos);
  			oos.writeObject(obj);
  			oos.close();
  
  			byte[] bytes = bos.toByteArray();
  			return bytes.length;
  		} catch (IOException ex) {
  			// Unable to serialize so cannot determine size.
  			return -1;
  		}
  	}
docs: Determines the serialized size of an object by serializng it to a byte array.
  
  @param obj the object to find the serialized size of.
  @return the serialized size of the given object, or -1 on error.