class_docstr: Trainer for label-cotuning
  calculate the relationship between base_classes and novel_classes
class_docstr_tok: ["Trainer","for","label-cotuning","calculate","the","relationship","between","base_classes","and","novel_classes"]
code: def cotuning_init(self):
      num_classes_novel = self.cfg["num_classes"]
  
      self.load_weights(self.cfg.pretrain_weights)
  
      self.model.eval()
      relationship = self.model.relationship_learning(
          self.loader, num_classes_novel
      )
  
      self.model.init_cot_head(relationship)
      self.optimizer = create("OptimizerBuilder")(self.lr, self.model)
  
imports: from ppdet.core.workspace import create
  from ppdet.utils.logger import setup_logger
  from .None import Trainer
label_desc: Use image node_id 2 for calling the TrainerCot obj's underlying member method code with example usage: obj.cotuning_init() without return types