text: Title: 如何同时训练两个模型？
  Body: ### Is there an existing issue for this bug?
  
  - [X] I have searched the existing issues
  
  ### 🐛 Describe the bug
  
  在官方文档中给出了训练一个model的例子：
  ```
  colossalai.launch(...)
  plugin = GeminiPlugin(...)
  booster = Booster(precision='fp16', plugin=plugin)
  
  model = GPT2()
  optimizer = HybridAdam(model.parameters())
  dataloader = plugin.prepare_dataloader(train_dataset, batch_size=8)
  lr_scheduler = LinearWarmupScheduler()
  criterion = GPTLMLoss()
  
  model, optimizer, criterion, dataloader, lr_scheduler = booster.boost(model, optimizer, criterion, dataloader, lr_scheduler)
  
  for epoch in range(max_epochs):
      for input_ids, attention_mask in dataloader:
          outputs = model(input_ids.cuda(), attention_mask.cuda())
          loss = criterion(outputs.logits, input_ids)
          booster.backward(loss, optimizer)
          optimizer.step()
          lr_scheduler.step()
          optimizer.zero_grad()
  ```
  
  如果在我的训练中，有两个模型model1和model2都需要被训练，应该如何使用训练呢？
  
  ### Environment
  
  _No response_