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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 retrieve_metrics(self):
 """Return the convergence metrics saved with the corresponding iterations. """


        time = np.array(self.list_dates)
        if len(time) >= 1:
            time -= time[0]
        return {'time': time, 'index': self.list_iters,
                'values': self.list_cv_values}