window.googletag = window.googletag || {cmd: []};
googletag.cmd.push(function() {
var mapping1 = googletag.sizeMapping().addSize([0,0],[300,50]).addSize([800,600],[1212,156]).build();
var mapping2 = googletag.sizeMapping().addSize([320, 700], [[300, 250]]).build();googletag.defineSlot(‘/4132421/DO-Leaderboard-1212×156’, [1212, 156], ‘div-gpt-ad-1517300133825-0’).defineSizeMapping(mapping1).addService(googletag.pubads());googletag.pubads().enableSingleRequest();googletag.enableServices();
});
Astute Class infographic.