getSite = ({url, lantern, wpt3g}) => ({
    url: url || 'http://example.com',
    wpt3g: {firstContentfulPaint: wpt3g},
    lantern: /** @type {LanternSite['lantern']} */ ({roughEstimateOfFCP: lantern}),
  })
@param {{url?: string, wpt3g: number, lantern: number}} param @return {LanternSite}