_createClass(RocketBrowserCompatibilityChecker,[{key:"_checkPassiveOption",value:function(self){try{var options={get passive(){return!(self.passiveSupported=!0)}};window.addEventListener("test",null,options),window.removeEventListener("test",null,options)}catch(err){self.passiveSupported=!1}}},{key:"initRequestIdleCallback",value:function(){!1 in window&&(window.requestIdleCallback=function(cb){var start=Date.now();return setTimeout(function(){cb({didTimeout:!1,timeRemaining:function(){return Math.max(0,50-(Date.now()-start))}})},1)}),!1 in window&&(window.cancelIdleCallback=function(id){return clearTimeout(id)})}},{key:"isDataSaverModeOn",value:function(){return"connection"in navigator&&!0===navigator.connection.saveData}},{key:"supportsLinkPrefetch",value:function(){var elem=document.createElement("link");return elem.relList&&elem.relList.supports&&elem.relList.supports("prefetch")&&window.IntersectionObserver&&"isIntersecting"in IntersectionObserverEntry.prototype}},{key:"isSlowConnection",value:function(){return"connection"in navigator&&"effectiveType"in navigator.connection&&("2g"===navigator.connection.effectiveType||"slow-2g"===navigator.connection.effectiveType)}}]),RocketBrowserCompatibilityChecker}();