istograms = new tr.v.HistogramSet();
    tr.metrics.sh.androidSystraceMetric(histograms, model);
    assert.lengthOf(histograms, 5);

    const assertHistValue = function(name, expectedValue) {
      const hist = histograms.getHistogramNamed(
          `android:systrace:threadtime:garbage_producer:${name}`);
      assert.strictEqual(hist.running.count, 1);
      assert.closeTo(hist.running.mean, expectedValue, 1e-5);
    };
    assertHistValue('running', 0.8);
    assertHistValue('runnable', 0);
    assertH