code: def _resolve_array_type(self):
          
          next_raw_dimension = self._next_raw_dimension
          if next_raw_dimension is None:
              return DT.CA
  
          is_mr_subvar = (
              next_raw_dimension._base_type == "categorical"
              and next_raw_dimension._has_selected_category
              and next_raw_dimension._alias == self._alias
          )
          return DT.MR if is_mr_subvar else DT.CA
docs: Return one of the ARRAY_TYPES members of DIMENSION_TYPE.
  
          This method distinguishes between CA and MR dimensions. The return
          value is only meaningful if the dimension is known to be of array
          type (i.e. either CA or MR, base-type 'enum.variable').