Updating Classifier and Predictor functions

Is it possible to update a classifier function by giving it new training data.
For example, given the statement:
c = Classify[{1, 2, 3, 4, 5} → {“A”, “B”, “C”, “D”, “E”}]

Is it possible to update c with new learning data with something like:
Update[c,{6->“F”, 7->“G”}]
Rather than have to recreate a classifier with all the data at that point as in:
c = Classify[{1, 2, 3, 4, 5, 6, 7} → {“A”, “B”, “C”, “D”, “E”, “F”, “G”}]
which could be expensive in time.
And of course, could the same thing be done with Predictor?

I wanted to do the same. However as I last checked with the support a couple of years ago, it wasn’t possible then.

It worked on NetTrain though, if I remember correctly.