tabnet_fit() with tabnet_model = plot the new checkpoints onto from_model metric history

[cregouby]

Scenario

fit_no_checkpoint <- tabnet_fit(Sale_Price ~., data = ames_train, epochs = 54, valid_split = 0.2, checkpoint_epoch = 55)
fit_with_checkpoint <- tabnet_fit(Sale_Price ~., data = ames_train, tabnet_model = fit_no_checkpoint,
                                   epochs = 6, valid_split = 0.2, checkpoint_epoch = 1)

Expected outcome

plot shows checkpoints onto the last 6 epoch

Actual result

plot shows checkpoints on the first 6 epochs