@Override
  public void toData(DataOutput out,
      SerializationContext context) throws IOException {
    out.writeInt(viewId);
    out.writeBoolean(preparing);
    context.getSerializer().writeObject(alternateView, out);
  }
Members receiving an InstallViewMessage must respond by sending a ViewAckMessage.
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messages/ViewAckMessage.java