# File lib/dnsruby/message/header.rb, line 121
  def Header.decrement_arcount_encoded(bytes)
    header = Header.new
    header_end = 0
    MessageDecoder.new(bytes) do |msg|
      header.decode(msg)
      header_end = msg.index
    end
    header.arcount -= 1
    bytes[0, header_end] = MessageEncoder.new { |msg| header.encode(msg) }.to_s
    bytes
  end