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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 get_choice_href(self):
 """ Returns the HREF of a dynamic choice parameter. Throws an error if this is not a choice parameter. """

        if 'choiceInfo' not in self.dto[self.name]:
            raise GPException('not a choice parameter')

        return self.dto[self.name]['choiceInfo']['href']