code: def __sub__(self, other):
      assert isinstance(other, StatSum)
      return StatSum(self.value - other.value)
  
imports: import copy
  import dataclasses
  import logging
  import torch
  import moolib
label_desc: Use image node_id 2 for calling the StatSum obj's underlying member method code with example usage: obj.__sub__(other) and returns: StatSum