code: function resolvedUrlFor (shortcode, size, cb) {
    if (typeof size === 'function') {
      cb = size
      size = 'l'
    }
    cb = cb || function () {}
  
    var apiUrl = apiUrlFor(shortcode, size)
  
    var opts = url.parse(apiUrl)
    // http requests use the global Agent (connection pool) and defaults to `Connection: keep-alive`
    // This causes the test suite to hang, so we explicitly set it to close.
    // Alternatively, set `opts.agent: false` to opt out of connection pool and default to `Connection: close`
    // see: http://nodejs.org/api/http.html#http_http_request_options_callback
    opts.headers = {
      Connection:'close'
    }
  
    http.get(opts, function (res) {
      var url = res && res.headers && res.headers.location
      if (!url) return cb(new Error('Couldn\'t get url; no `location` header on response'), res)
      cb(null, url)
  
    }).on('error', cb)
  }
docs: Grab the location header from the initial response.