code: def _subtract(summary, o):
      
      found = False
      row = [_repr(o), 1, _getsizeof(o)]
      for r in summary:
          if r[0] == row[0]:
              (r[1], r[2]) = (r[1] - row[1], r[2] - row[2])
              found = True
      if not found:
          summary.append([row[0], -row[1], -row[2]])
      return summary
docs: Remove object o from the summary by subtracting it's size.