code: function download(url,onError) {
      var request = require('request');
  
      util.log('Downloading cef tarball for '+platform+'-'+arch+'...');
  
      var requestOpts = {
          uri: url,
          onResponse: true
      }
  
      // basic support for a proxy server
      var proxyUrl = process.env.http_proxy
                  || process.env.HTTP_PROXY
                  || process.env.npm_config_proxy
      if (proxyUrl) {
        util.log('using proxy: ' + proxyUrl,'verbose');
        requestOpts.proxy = proxyUrl
      }
      return request(requestOpts).on('error',onError).on('response',function(res){onError(null,res)});
  }
docs: Returns a Request object