code: def test_dpo_lora_bf16_autocast_llama(self):
      # Note this test only works on compute capability > 7 GPU devices
      from peft import LoraConfig
  
      model_id = "HuggingFaceM4/tiny-random-LlamaForCausalLM"
      tokenizer = AutoTokenizer.from_pretrained(model_id)
  
      lora_config = LoraConfig(
          r=16,
          lora_alpha=32,
          lora_dropout=0.05,
          bias="none",
          task_type="CAUSAL_LM",
      )
  
      # lora model
      model = AutoModelForCausalLM.from_pretrained(
          model_id, load_in_4bit=True
      )
  
      with tempfile.TemporaryDirectory() as tmp_dir:
          training_args = TrainingArguments(
              output_dir=tmp_dir,
              per_device_train_batch_size=2,
              max_steps=3,
              remove_unused_columns=False,
              gradient_accumulation_steps=4,
              learning_rate=9e-1,
              evaluation_strategy="steps",
              bf16=True,
          )
  
          dummy_dataset = self._init_dummy_dataset()
  
          # dpo train lora model with a lora config
          trainer = DPOTrainer(
              model=model,
              ref_model=None,
              beta=0.1,
              args=training_args,
              tokenizer=tokenizer,
              train_dataset=dummy_dataset,
              eval_dataset=dummy_dataset,
              peft_config=lora_config,
              generate_during_eval=True,
          )
  
          # train the model
          trainer.train()
  
          # save peft adapter
          trainer.save_model()
  
imports: import tempfile
  import unittest
  import torch
  from datasets import Dataset
  from parameterized import parameterized
  from pytest import mark
  from transformers import AutoModelForCausalLM, AutoModelForSeq2SeqLM, AutoTokenizer, TrainingArguments
  from trl import DPOTrainer
  from .testing_utils import require_bitsandbytes, require_no_wandb, require_peft
label_desc: Use image node_id 9 for calling the DPOTrainerTester obj's underlying member method code with example usage: obj.test_dpo_lora_bf16_autocast_llama() without return types