code: function() {
      var x_start = this.bar_padding + this.options.plot_padding,
          step = this.step;
      if (this.grouped) {
        step = step * this.group_size;
        x_start = ((this.bar_width * this.group_size) + (this.bar_padding * this.group_size)) / 2
        x_start = this.roundValue(x_start, 0);
      }
      this.drawMarkers(this.options.labels, [1, 0], step, x_start, [0, (this.options.font_size + 7) * -1]);
    }
docs: /* Change the standard options to correctly offset against the bars