docs: def _get_part(pointlist, strokes):
      """Get some strokes of pointlist
  
      Parameters
      ----------
      pointlist : list of lists of dicts
      strokes : list of integers
  
      Returns
      -------
      list of lists of dicts
      """
      result = []
      strokes = sorted(strokes)
      for stroke_index in strokes:
          result.append(pointlist[stroke_index])
      return result