@Override
  public void toData(DataOutput out,
      SerializationContext context) throws IOException {
    super.toData(out, context);
    out.writeInt(bucketId); // fix for bug 38228
  }
Sends a BucketSize message to determine the number of bytes the bucket consumes

@param recipient the member that the contains keys/value message is sent to
@param r the PartitionedRegion that contains the bucket
@param bucketId the identity of the bucket whose size should be returned.
@return the processor used to read the returned size
@throws ForceReattemptException if the peer is no longer available
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/BucketSizeMessage.java