code: def reset(self):
      raise NotImplementedError(
          "Custom Metrics must implement this function"
      )
  
imports: import torch
  from .utils import th_matrixcorr
  from .meters.averagemeter import AverageMeter
  from .callbacks import Callback
  from .losses import lovaszloss, hingeloss, dice_coeff
label_desc: Use image node_id 2 for calling the Metric obj's underlying member method code with example usage: obj.reset() without return types