Updates the model with new observations.

def updateModel(self, X_all, Y_all, X_new, Y_new):
        """
        Updates the model with new observations.
        """
        self.X = X_all
        self.Y = Y_all
        if self.model is None:
            self._create_model(X_all, Y_all)
        else:
            self.model.fit(X_all, Y_all.flatten())