code: def configure_optimizers(self):
      # FIXME: Doesn't support LRScheduler yet
      return list(
          itertools.chain(
              *[t.configure_optimizers() for t in self._trainers]
          )
      )
  
imports: import bisect
  import functools
  import itertools
  from collections import OrderedDict
  from typing import Dict, List, Tuple
  import torch.nn
  from pytorch_lightning.loops.optimization.optimizer_loop import ClosureResult
  from reagent.core.utils import lazy_property
  from .reagent_lightning_module import ReAgentLightningModule
label_desc: Use image node_id 11 for calling the MultiStageTrainer obj's underlying member method code with example usage: obj.configure_optimizers() and returns: list