# File lib/dragonfly/server.rb, line 60
    def url_for(job, opts={})
      opts = opts.dup
      host = opts.delete(:host) || url_host
      params = stringify_keys(opts)
      params['job'] = job.serialize
      params['sha'] = job.sha if protect_from_dos_attacks
      url = url_mapper.url_for(params)
      "#{host}#{url}"
    end