protected long getAttributeSize() {
    long size = 0;
    if (attributes != null) {
      size += ClassSize.align(this.attributes.size() * ClassSize.MAP_ENTRY);
      for (Map.Entry<String, byte[]> entry : this.attributes.entrySet()) {
        size += ClassSize.align(ClassSize.STRING + entry.getKey().length());
        size += ClassSize.align(ClassSize.ARRAY + entry.getValue().length);
      }
    }
    return size;
  }
empty construction. We need this empty construction to keep binary compatibility.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/OperationWithAttributes.java