code: def _base_type(self):
          
          type_class = self._dimension_dict["type"]["class"]
          if type_class == "categorical":
              return "categorical"
          if type_class == "enum":
              subclass = self._dimension_dict["type"]["subtype"]["class"]
              return "enum.%s" % subclass
          raise NotImplementedError("unexpected dimension type class '%s'" % type_class)
docs: Return str like 'enum.numeric' representing dimension type.
  
          This string is a 'type.subclass' concatenation of the str keys
          used to identify the dimension type in the cube response JSON.
          The '.subclass' suffix only appears where a subtype is present.