code: function(imageUrl, callback) {
          var url = imageUrl.clone(),
              extension = url.getExtension(),
              imageId = url.getImageIdentifier(),
              host = this.getHostForImageIdentifier(imageId);
  
          var data = {
              imageIdentifier: imageId,
              user: url.getUser(),
              publicKey: url.getPublicKey(),
              query: url.getQueryString()
          };
  
          if (extension) {
              data.extension = extension;
          }
  
          // Reset to remove transformations/query string
          url.reset().setPath('/shorturls');
  
          request({
              method: 'POST',
              uri: this.getSignedResourceUrl('POST', url.toString()),
              json: data,
              onComplete: function(err, res, body) {
                  if (err) {
                      return callback(err);
                  } else if (!body || !body.id) {
                      return callback('No ShortUrl was returned from server');
                  }
  
                  callback(err, new ShortUrl({ baseUrl: host, id: body.id }));
              }
          });
  
          return this;
      }
docs: Get the short URL of an image (with optional transformations)
  
  @param {Imbo.ImageUrl} imageUrl
  @param {Function}      callback
  @return {ImboClient}