TreeTable - refreshNode method missing

We are using Vaadin 7.6.8 and we find that the TreeTable refresh takes a huge amount of time to load. There are instances where we need to refresh the table and that takes a good load of time. We could avoid the full table refresh, if there was something like a refreshRow / refreshNode method like what we have for a Grid. Is there any reason of not having a method to refresh a specific node / row of the TreeTable.