tener_);
      // Don't need to removeUpdateListener for the row and cells; their
      // lifetimes are the same as |this|.
    },

    updateMwu_() {
      const referenceHistogram = this.referenceHistogram;
      this.mwuResult_ = undefined;
      if (!(this.histogram instanceof tr.v.Histogram)) return;
      if (!this.histogram.canCompare(referenceHistogram)) return;
      this.mwuResult_ = tr.b.math.Statistics.mwu(
          this.histogram.sampleValues,
          referenceHistogram.sampleValues,
      