code: function (index) {
        var $rating = this.$rating;
        // Get the index of the last whole symbol.
        var i = Math.floor(index);
        // Hide completely hidden symbols background.
        $rating.find('.rating-symbol-background')
          .css('visibility', 'visible')
          .slice(0, i).css('visibility', 'hidden');
        var $rates = $rating.find('.rating-symbol-foreground');
        // Reset foreground
        $rates.width(0);
        // Fill all the foreground symbols up to the selected one.
        $rates.slice(0, i).width('auto')
          .find('span').attr('class', this.options.filled);
        // Amend selected symbol.
        $rates.eq(index % 1 ? i : i - 1)
          .find('span').attr('class', this.options.filledSelected);
        // Partially fill the fractional one.
        $rates.eq(i).width(index % 1 * 100 + '%');
      }
docs: Fill rating symbols until index.