Dart Null Safety Beta

I really like Swift syntax. Declarations basically are the same in Dart's. But I couldn't find a Dart equivalence for the following bit of Swift:

    if let sample = cachedSample, searchResult.isRecent {
        sampleViewModel.mode = .success(sample)
    } else {
        sampleViewModel.getSample(number: sampleNumber)
    }

Do they have plans for that as well?