code: def initialize_loss_weights(self):
      if self.loss_weights is None:
          self.loss_weights = {k: 1 for k in self.loss_names}
  
imports: import torch
  import tqdm
  from ..utils import common_functions
  from ..utils import loss_tracker
  from ..utils.key_checker import KeyChecker, KeyCheckerDict
label_desc: Use image node_id 30 for calling the BaseTrainer obj's underlying member method code with example usage: obj.initialize_loss_weights() without return types