docs: def get_by_id(self, style_id, style_type):
          """Return the style of *style_type* matching *style_id*.
  
          Returns the default for *style_type* if *style_id* is not found or is |None|, or
          if the style having *style_id* is not of *style_type*.
          """
          if style_id is None:
              return self.default(style_type)
          return self._get_by_id(style_id, style_type)