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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 default_value(self):
 """ Generate a default value :return: the value """

        if self.has_default:
            if hasattr(self.default, '__call__'):
                return self.default()
            else:
                return self.default
        else:
            raise Exception("No default value specified")