# File lib/action_view/helpers/asset_tag_helpers/stylesheet_tag_helpers.rb, line 44
          def register_stylesheet_expansion(expansions)
            style_expansions = StylesheetIncludeTag.expansions
            expansions.each do |key, values|
              style_expansions[key] = (style_expansions[key] || []) | Array(values)
            end
          end