async getArtifact(passContext) {
    const driver = passContext.driver;

    const dimensions = await driver.executionContext.evaluate(getViewportDimensions, {
      args: [],
      useIsolation: true,
    });

    const allNumeric = Object.values(dimensions).every(Number.isFinite);
    if (!allNumeric) {
      const results = JSON.stringify(dimensions);
      throw new Error(`ViewportDimensions results were not numeric: ${results}`);
    }

    return dimensions;
  }
@param {LH.Gatherer.Context} passContext
@return {Promise<LH.Artifacts.ViewportDimensions>}