class Kafka::Protocol::OffsetCommitRequest

def encode(encoder)
  encoder.write_string(@group_id)
  encoder.write_int32(@generation_id)
  encoder.write_string(@member_id)
  encoder.write_int64(@retention_time)
  encoder.write_array(@offsets) do |topic, partitions|
    encoder.write_string(topic)
    encoder.write_array(partitions) do |partition, offset|
      encoder.write_int32(partition)
      encoder.write_int64(offset)
      encoder.write_string(nil) # metadata
    end
  end
end