code: function(options) {
          var params = [],
              opts = options || {};
  
          if (isNumeric(opts.brightness) || isNumeric(opts.b)) {
              params.push('b=' + (opts.brightness || opts.b));
          }
  
          if (isNumeric(opts.saturation) || isNumeric(opts.s)) {
              params.push('s=' + (opts.saturation || opts.s));
          }
  
          if (isNumeric(opts.hue) || isNumeric(opts.h)) {
              params.push('h=' + (opts.hue || opts.h));
          }
  
          if (!params.length) {
              throw new Error('brightness, saturation or hue needs to be specified');
          }
  
          return this.append('modulate:' + params.join(','));
      }
docs: Modulate the image by altering the brightness, saturation and/or hue
  
  @param  {Object} options
  @param  {Number} [options.brightness=100] Brightness level
  @param  {Number} [options.saturation=100] Saturation level
  @param  {Number} [options.hue=100]        Hue level
  @return {Imbo.ImageUrl}