class Mail::CommonMessageIdField

def default
  ids = message_ids
  ids.one? ? ids.first : ids
end

def do_decode
  formatted_message_ids
end

def do_encode
  %Q{#{name}: #{formatted_message_ids("\r\n ")}\r\n}
end

def element
  @element ||= Mail::MessageIdsElement.new(value)
end

def formatted_message_ids(join = ' ')
  message_ids.map { |m| "<#{m}>" }.join(join) if message_ids.any?
end

def message_id
  element.message_id
end

def message_ids
  element.message_ids
end

def to_s
  decoded.to_s
end