No callback when cancel fetch Appcast

[colin1994]

- (void)appcastDidFinishLoading:(SUAppcast *)ac
{
    if (self.isCanceled)
    {
        [self abortUpdate];
        return;
    }
    [self closeCheckingWindow];
    [super appcastDidFinishLoading:ac];
}

During the fetchAppcastFromURL process, if cancel is clicked, it will abort directly. There is no callback.

We want to get this status, is it feasible? Thank you!