  const path = [
      [CHROME_PROCESS_NAMES.BROWSER],
      ['Worker'], ['all_stages', 'all_initiators']
    ];

    const model = buildModelFromSpec(modelSpec);
    const root = constructMultiDimensionalView(model, model.bounds);
    const values = getNodeValues_(root, path);

    assert.closeTo(getCpuUsage_(values), (250 + 400) / 990, 1e-7);
    assert.closeTo(getCpuTotal_(values), 250 + 400, 1e-7);
  });

  /**
   * Returns a model spec where there are two renderer processes, each with a
   * renderer m