Future<Null> writeSummaryToFile(String traceName, { String destinationDirectory, bool pretty: false })

Writes summaryJson to a file.

Source 

Future<Null> writeSummaryToFile(String traceName,
    {String destinationDirectory, bool pretty: false}) async {
  destinationDirectory ??= testOutputsDirectory;
  await fs.directory(destinationDirectory).create(recursive: true);
  File file = fs.file(path.join(destinationDirectory, '$traceName.timeline_summary.json'));
  await file.writeAsString(_encodeJson(summaryJson, pretty));
}