code: def _aux_type(self, i):
          
          aux_type = ctypes.c_int()
          check_call(_LIB.MXNDArrayGetAuxType(self.handle, i, ctypes.byref(aux_type)))
          return _DTYPE_MX_TO_NP[aux_type.value]
docs: Data-type of the array's ith aux data.
  
          Returns
          -------
          numpy.dtype
              This BaseSparseNDArray's aux data type.