i18n builder method

i18n_builder_method.rb

def set_contents_builder model_obj
  model_name = model_obj.class.name.downcase
  accociation = model_obj.send("#{model_name}_contents").group_by {|content| content.lang}
  if accociation['ru'].nil?
    model_obj.send("#{model_name}_contents").build(lang: 'ru')
  end
  if accociation['en'].nil?
    model_obj.send("#{model_name}_contents").build(lang: 'en')
  end
end