code: def handle_na(self, data):
          
          return remove_missing(data,
                                self.params['na_rm'],
                                list(self.REQUIRED_AES | self.NON_MISSING_AES),
                                self.__class__.__name__)
docs: Remove rows with NaN values
  
          geoms that infer extra information from missing values
          should override this method. For example
          :class:`~plotnine.geoms.geom_path`.
  
          Parameters
          ----------
          data : dataframe
              Data
  
          Returns
          -------
          out : dataframe
              Data without the NaNs.
  
          Notes
          -----
          Shows a warning if the any rows are removed and the
          `na_rm` parameter is False. It only takes into account
          the columns of the required aesthetics.