mirror_files_for (Merb::Slices::ModuleMixin)

    # 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