code: public int createPartitions(String topic, int partitionNum, boolean enlarge) throws IOException {
          KV<Receive, ErrorMapping> response = send(new CreaterRequest(topic, partitionNum, enlarge));
          return Utils.deserializeIntArray(response.k.buffer())[0];
      }
docs: create partitions in the broker
  
  @param topic topic name
  @param partitionNum partition numbers
  @param enlarge enlarge partition number if broker configuration has
  setted
  @return partition number in the broker
  @throws IOException if an I/O error occurs