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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 to_dict(self):
        '''Save this configuration set into a dictionary.'''
        d = {'id': self.id}
        data = []
        for c in self._config_data:
            data.append(c.to_dict())
        if data:
            d['configurationData'] = data
        return d