class_docstr: Trainer for ensemble models
  
  Attributes:
      real_trainer (Trainer): the actual trainer to run
code: def train(self, train_iter, eval_iter, model, *args, **kwargs):
      for m, t in zip(model.models, self.real_trainers):
          t.train(train_iter, eval_iter, m, *args, **kwargs)
      model.merge_sub_models()
      return model, None
  
file_path: pytext/pytext/trainers/ensemble_trainer.py
imports: import torch
  from pytext.config import ConfigBase
  from pytext.config.component import create_trainer
  from .trainer import TaskTrainer, TrainerBase
label_desc: Use image node_id 3 for calling the EnsembleTrainer obj's underlying member method code with example usage: obj.train(train_iter, eval_iter, model) and returns: model,  None