throwIfCancelled method
      
void
throwIfCancelled()
      
     
    
Throws the cancellation exception if the token has already been cancelled.
Implementation
void throwIfCancelled() {
  if (isCancelled) throw exception!;
}
Throws the cancellation exception if the token has already been cancelled.
void throwIfCancelled() {
  if (isCancelled) throw exception!;
}