code: protected byte[] flattenAction (NodeAction action)
      {
          try {
              ByteArrayOutputStream bout = new ByteArrayOutputStream();
              ObjectOutputStream oout = new ObjectOutputStream(bout);
              oout.writeObject(action);
              return bout.toByteArray();
          } catch (Exception e) {
              throw new IllegalArgumentException(
                  "Failed to serialize node action [action=" + action + "].", e);
          }
      }
docs: Flattens the supplied node action into bytes.