public override void Progress(ImportStage stage, int percent) { if (percent > 100) { fail("Expected percentage to be 0..100% but was " + percent); } AtomicInteger stageProgress = ProgressConflict.computeIfAbsent(stage, s => new AtomicInteger()); int previous = stageProgress.getAndSet(percent); if (previous > percent) { fail("Progress should go forwards only, but went from " + previous + " to " + percent); } }