how slight ask collection activerecord objects

currently, i wish ask slight organisation activerecord objects, i have structure so:

messages = message.find(:all)
csv = message.to_csv(messages)

how i interpretation slight it's structured so?

messages = message.find(:all)
csv = messages.to_csv

this tide denote code:

require 'fastercsv'
class summary < activerecord::base
  def message.to_csv(messages)
    fastercsv.generate |csv|
      csv << ["from","to", "received"]
      m messages
        csv << [m.from,m.to,m.created_at]
      end
    end
  end
end