code: def step(self, epoch=None):
      if epoch is None:
          epoch = self.last_epoch + 1
  
      self.last_epoch = epoch
      new_momemtum = self.bn_lambda(epoch)
      if self._current_momemtum != new_momemtum:
          self._current_momemtum = new_momemtum
          log.info(
              "Setting batchnorm momentum at {}".format(new_momemtum)
          )
          self.model.apply(self.setter(new_momemtum))
  
file_path: torch-points3d/torch_points3d/core/schedulers/bn_schedulers.py
imports: from typing import *
  from omegaconf import OmegaConf
  from torch import nn
  import logging
label_desc: Use image node_id 5 for calling the BNMomentumScheduler obj's underlying member method code with example usage: obj.step(epoch) without return types