const observer =newPerformanceObserver(
(list, observer, options)=>{
for(const entry of list.getEntries()){
console.log(
'Received entry with type',
 entry.entryType,
'and name',
 entry.name,
'that started at',
 entry.startTime,
'and took',
 entry.duration,
'ms',
);
}
},
);

observer.observe({entryTypes:['mark','measure']});