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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 set(self, key, data):
        '''
        set arbitrary data by key in volatile memory

        :param key: key of the data
        :param data: data to be stored
        '''
        if isinstance(data, dict):
            self._volatile_data[key] = {k: v for (k, v) in data.items()}
        else:
            self._volatile_data[key] = data