code: function(url, callback) {
          if (isBrowser) {
              // Browser environments can't pipe, so download the file and add it
              return this.getImageDataFromUrl(url, function(err, data) {
                  if (err) {
                      return callback(err);
                  }
  
                  this.addImageFromBuffer(data, callback);
              }.bind(this));
          }
  
          // Pipe the source URL into a POST-request
          request({ uri: url }).pipe(request({
              method: 'POST',
              uri: this.getSignedResourceUrl('POST', this.getImagesUrl()),
              json: true,
              headers: {
                  'Accept': 'application/json',
                  'User-Agent': 'imboclient-js'
              },
              onComplete: function(err, res, body) {
                  callback(err, body ? body.imageIdentifier : null, body, res);
              }
          }));
  
          return this;
      }
docs: Add an image from a remote URL
  
  @param {String}   url
  @param {Function} callback
  @return {ImboClient}