# File lib/jeweler/gemspec_helper.rb, line 58
    def normalize_files(array_attribute)
      array = @spec.send(array_attribute)
      # only keep files, no directories, and sort
      array = array.select do |path|
        File.file? File.join(@base_dir, path)
      end.sort

      @spec.send("#{array_attribute}=", array)
    end