code: def reset(self):
      if self.mat is not None:
          self.mat.zero_()
  
imports: from collections import defaultdict, deque
  import datetime
  import time
  import torch
  import torch.distributed
  import errno
  import os
label_desc: Use image node_id 3 for calling the ConfusionMatrix obj's underlying member method code with example usage: obj.reset() without return types