# File lib/jammit/compressor.rb, line 140
    def concatenate_and_tag_assets(paths, variant=nil)
      stylesheets = [paths].flatten.map do |css_path|
        contents = read_binary_file(css_path)
        contents.gsub(EMBED_DETECTOR) do |url|
          ipath, cpath = Pathname.new($1), Pathname.new(File.expand_path(css_path))
          is_url = URI.parse($1).absolute?
          is_url ? url : "url(#{construct_asset_path(ipath, cpath, variant)})"
        end
      end
      stylesheets.join("\n")
    end