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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_selected_value(self):
 """ Returns the default selection from a choice menu Throws an error if this is not a choice parameter. """

        if 'choiceInfo' not in self.dto[self.name]:
            raise GPException('not a choice parameter')
        choice_info_dto = self.dto[self.name]['choiceInfo']
        if 'selectedValue' in choice_info_dto:
            return self.dto[self.name]['choiceInfo']['selectedValue']
        else:
            return None