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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 _aux_types(self):
 """The data types of the aux data for the BaseSparseNDArray. """

        aux_types = []
        num_aux = self._num_aux
        for i in range(num_aux):
            aux_types.append(self._aux_type(i))
        return aux_types