code: def dom_classes
        if positive?
          t 'comparison.dom_classes.positive',
            default: %i[comparison.classes.positive]
        elsif negative?
          t 'comparison.dom_classes.negative',
            default: %i[comparison.classes.negative]
        else
          t 'comparison.dom_classes.nochange',
            default: %i[comparison.classes.nochange]
        end
      end
docs: Returns the I18n translation for `comparison.dom_classes`.
  
   Use these translations to specify CSS classes for tags that contain
   comparison data. For example:
  
       en:
         comparison:
           dom_classes:
             positive: 'comparison positive'
             negative: 'comparison negative'
             nochange: 'comparison nochange'
  
       .comparison.positive {
         color: #3c763d;
         background-color: #dff0d8;
       }
       .comparison.negative {
         color: #a94442;
         background-color: #f2dede;
       }
       .comparison.nochange {
         color: #777777;
       }
  
       content_tag :span, cmp.difference, class: cmp.dom_classes
       # => "<span class=\"comparison positive\">+10%</span>"
  
   If you need to work with inline styles instead of CSS classes, see the
   `#style` method.