Flattens an AggregateException instances into a single, new instance.
Assemblies: mscorlib (in mscorlib.dll)
System.Threading.Tasks (in System.Threading.Tasks.dll)
If any inner exceptions are themselves instances of AggregateException, this method will recursively flatten all of them. The inner exceptions returned in the new AggregateException will be the union of all of the the inner exceptions from exception tree rooted at the provided AggregateException instance.