istogram)) {
        throw new Error('Invalid Histogram: ' + this.histogram);
      }

      if (this.histogram.numValues === 0) {
        this.$.empty.style.display = 'block';
        return;
      }

      this.$.open_histogram.style.display = 'block';
      this.$.open_histogram.style.visibility = 'visible';
      this.$.scalar.style.display = 'flex';

      this.updateSignificance_();

      const referenceHistogram = this.referenceHistogram;
      const statName = this.histogram.getAvailableStatisticNa