unnecessarily introducing mutable state

unnecessarily.rb

class RssImporter
  attr_writer :articles
  attr_reader :result
   
  def import
    @result = articles.map do |article|
      RssContent.create { url: article.url, text: article.body }
    end
  end
end

# consuming the RssImporter...

importer = RssImporter.new
importer.articles = a_bunch_of_rss_content
importer.import
imported = importer.result