# File lib/merb-slices/module_mixin.rb, line 393
      def mirror_files_for(*types)
        seen, copied, duplicated = [], [], [] # keep track of files we copied
        types.flatten.each do |type|
          if app_paths.key?(type) && (source_path = dir_for(type)) && (destination_path = app_dir_for(type))
            manifest(type).each do |source, relative_path| # this relative path is not what we need here
              next if seen.include?(source)
              mirror_file(source, destination_path / source.relative_path_from(source_path), copied, duplicated)
              seen << source
            end
          end
        end
        [copied, duplicated]
      end