I want to measure durations using Timeline class in flutter, how to do it for multiple parallel tasks?

Question

dart timeline works with a stack, but I am trying to measure traces of 10-15 asynchronous tasks which are running on UI thread, I am trying to do app startup profiling using Dev tools->timeline.

I am doing their start sync simultaneously , how will it correctly determine which one finishes first ? Right now it is not determining it correctly, as it is finishing off the last added task.

syntax :

     Timeline.startSync('name of the task : ${this.name} description:$description}');
     Timeline.finishSync();