code: def configure_optimizers(self):
      # no optimizers bcs we update state manually
      return None
  
file_path: ReAgent/reagent/training/cb/mab_trainer.py
imports: import logging
  from reagent.core.types import CBInput
  from reagent.gym.policies.policy import Policy
  from reagent.models.mab import MABBaseModel
  from reagent.training.cb.base_trainer import BaseCBTrainerWithEval
label_desc: Use image node_id 3 for calling the MABTrainer obj's underlying member method code with example usage: obj.configure_optimizers() and returns: None