code: def delete(self, shape=None, part=None, point=None):
          
          # shape, part, point
          if shape and part and point:
              del self._shapes[shape][part][point]
          # shape, part
          elif shape and part and not point:
              del self._shapes[shape][part]
          # shape
          elif shape and not part and not point:
              del self._shapes[shape]
          # point
          elif not shape and not part and point:
              for s in self._shapes:
                  if s.shapeType == 1:
                      del self._shapes[point]
                  else:
                      for part in s.parts:
                          del s[part][point]
          # part, point
          elif not shape and part and point:
              for s in self._shapes:
                  del s[part][point]
          # part
          elif not shape and part and not point:
              for s in self._shapes:
                  del s[part]
docs: Deletes the specified part of any shape by specifying a shape
          number, part number, or point number.