Let browserSupportsPassiveEvents
browserSupportsPassiveEvents: boolean = (() => {// https://github.com/WICG/EventListenerOptions/blob/gh-pages/explainer.md#feature-detectionlet supportsPassive = falsetry {let opts = Object.defineProperty({}, 'passive', {get: function() {supportsPassive = true}});window.addEventListener("test", null, opts)} catch (e) {}return supportsPassive})()