@Override protected TimelineV2 schema(int version) { return new TimelineV2(); }
@Override public void compute2() { throw H2O.unimpl(); }
// TODO: should return a base class for TimelineVx
public TimelineV2 fetch(int version, Timeline t) {
t.snapshot = new TimelineSnapshot(H2O.CLOUD,TimeLine.system_snapshot());
return schema(version).fillFromImpl(t);
}