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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 summary(self):
 """ Summary of model definition for labeling. Intended to be somewhat readable but unique to a given model definition. """

        if self.features is not None:
            feature_count = len(self.features)
        else:
            feature_count = 0
        feature_hash = 'feathash:' + str(hash(tuple(self.features)))
        return (str(self.estimator), feature_count, feature_hash, self.target)