# File lib/rubytorrent/message.rb, line 68
  def to_wire_form
    case @id
    when :keepalive
      0.to_fbbe
    when :choke, :unchoke, :interested, :uninterested
      1.to_fbbe + WIRE_IDS.index(@id).chr
    when :have
      5.to_fbbe + 4.chr + @args[:index].to_fbbe
    when :bitfield
      (@args[:bitfield].length + 1).to_fbbe + 5.chr + @args[:bitfield]
    when :request, :cancel
      13.to_fbbe + WIRE_IDS.index(@id).chr + @args[:index].to_fbbe +
        @args[:begin].to_fbbe + @args[:length].to_fbbe
    when :piece
      (@args[:length] + 9).to_fbbe + 7.chr + @args[:index].to_fbbe +
        @args[:begin].to_fbbe
    else
      raise "unknown message type #{id}"
    end
  end