void addError(Object error, [ StackTrace stackTrace ])

Sends or enqueues an error event.

If error is null, it is replaced by a NullThrownError.

Listeners receive this event at a later microtask. This behavior can be overridden by using sync controllers. Note, however, that sync controllers have to satisfy the preconditions mentioned in the documentation of the constructors.

Source

void addError(Object error, [StackTrace stackTrace]) {
  _controller.addError(error, stackTrace);
}