class Berkshelf::Downloader

def download(*args, &block)
  # options are ignored
  # options = args.last.is_a?(Hash) ? args.pop : Hash.new
  dependency, version = args
  sources.each do |source|
    if ( result = try_download(source, dependency, version) )
      if block_given?
        value = yield result
        FileUtils.rm_rf(result)
        return value
      end
      return result
    end
  end
  raise CookbookNotFound.new(dependency, version, "in any of the sources")
end