private void recordJson(string json, object source)
{
_history.Record(json);
enableUndoRedo();
publish(source);
}
public void record_the_first_version()
{
history.Record("a");
history.CanGoBack.ShouldBeFalse();
history.CanGoForward.ShouldBeFalse();
history.Current.ShouldEqual("a");
}