code: def accumulate(self, axis: AxisIdentifier) -> HistogramBase:
          
          # TODO: Merge with Histogram1D.cumulative_frequencies
          # TODO: Deal with errors and totals etc.
          # TODO: inplace
          new_one = self.copy()
          axis_id = self._get_axis(axis)
          new_one._frequencies = np.cumsum(new_one.frequencies, axis_id[0])
          return new_one
docs: Calculate cumulative frequencies along a certain axis.
  
          Returns
          -------
          new_hist: Histogram of the same type & size