> Developer tool console
› var anchorsInArea = new AnchorsInArea()
undefined
› anchorsInArea
› window.scrollTo(0, 0)
› anchorsInArea.find({ top: 10, left: 10, right: 300, bottom: 300 })
› debug
› debug.setRange({ top: 10, left: 10, right: 300, bottom: 300 })
› debug.setRange({ top: 10, left: 10, width: 290, height: 290 })
› debug.setRange({ page:{ top: 10, left: 10 }, width: 290, height: 290 })
› debug.setRange({ top: 50, left: 60, right: 300, bottom: 300 })
› debug.setRange({ top: 50, left: 60, width: 240, height: 250 })
› debug.find()
› debug.setRange({ top: 30, left: 160, right: 700, bottom: 300 })