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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def update_terminal_regions(self, tree, X, y, residual, y_pred, sample_weight, sample_mask, learning_rate=1.0, k=0):
 """Least squares does not need to update terminal regions. But it has to update the predictions. """

        # update predictions
        y_pred[:, k] += learning_rate * tree.predict(X).ravel()