How to user verifyNever

I'm trying to use verifyNever to test that a function should not be called in a specific case, but it seems that doesn't work. Moreover, I've seen from:How to verify to call or not to call a method that to verify that something has been called you have to await for that, but how can I await for something that never happens? For example:

test('when create, should not call destroy', (){
    when(_mockCreateCharacter(name, surname)).thenThrow(exception);

      _bloc.dispatch(Create(name,surname));

      verifyNever(_bloc.destroy());
    });