Calling `ReactDefaultPerf.printWasted()` results in:

```
Uncaught TypeError: Cannot read property 'forEach' of undefined
writes.(anonymous function).forEach @ ReactDefaultPerfAnalysis.js:195
Object.keys.forEach @ ReactDefaultPerfAnalysis.js:192
getUnchangedComponents @ ReactDefaultPerfAnalysis.js:191
getInclusiveSummary @ ReactDefaultPerfAnalysis.js:139
ReactDefaultPerf.getMeasurementsSummaryMap @ ReactDefaultPerf.js:118
ReactDefaultPerf.printWasted @ ReactDefaultPerf.js:133
```

(this is on a page internally at Facebook so I assume it's a fairly recent React version)

var totalTime = 0;
  for (var i = 0; i < measurements.length; i++) {
    var measurement = measurements[i];
    totalTime += measurement.totalTime;
  }
  return totalTime;
}
function getDOMSummary(measurements) {