code: def setUpClass(cls):
      cls.dataset = load_dataset(
          "trl-internal-testing/mlabonne-chatml-dpo-pairs-copy",
          split="train[:10%]",
      )
      cls.peft_config = LoraConfig(
          lora_alpha=16,
          lora_dropout=0.1,
          r=8,
          bias="none",
          task_type="CAUSAL_LM",
      )
      cls.max_length = 128
  
imports: import gc
  import itertools
  import tempfile
  import unittest
  import torch
  from accelerate.utils.memory import release_memory
  from datasets import load_dataset
  from parameterized import parameterized
  from transformers import AutoModelForCausalLM, AutoTokenizer, BitsAndBytesConfig, TrainingArguments
  from trl import DPOTrainer, is_peft_available
  from ..testing_utils import require_bitsandbytes, require_peft, require_torch_gpu, require_torch_multi_gpu
  from .testing_constants import DPO_LOSS_TYPES, DPO_PRECOMPUTE_LOGITS, GRADIENT_CHECKPOINTING_KWARGS, MODELS_TO_TEST
label_desc: Use image node_id 1 for calling the DPOTrainerSlowTester obj's underlying member method code with example usage: obj.setUpClass(cls) without return types