@Override
  public void toData(DataOutput out,
      SerializationContext context) throws IOException {
    super.toData(out, context);
    out.writeInt(processorId);
  }
Sends a ping message. The pre-GFXD_101 recipients are filtered out and it is assumed that they
are pingable.

@return true if all the recipients are pingable
geode-core/src/main/java/org/apache/geode/internal/cache/ServerPingMessage.java