Update trainer.py

src/llmtuner/train/sft/trainer.py

 import json
 import os
+from types import MethodType
 from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple, Union
 
 import numpy as np
@@ -9,8 +10,7 @@ from transformers import Seq2SeqTrainer
 from ...extras.constants import IGNORE_INDEX
 from ...extras.logging import get_logger
 from ..utils import create_custom_optimzer, create_custom_scheduler
-from types import MethodType
-from packaging import version
+
 
 if TYPE_CHECKING:
     from transformers.trainer import PredictionOutput
@@ -31,6 +31,7 @@ class CustomSeq2SeqTrainer(Seq2SeqTrainer):
         self.finetuning_args = finetuning_args
         if finetuning_args.use_badam:
             from badam import clip_grad_norm_for_sparse_tensor
+
             self.accelerator.clip_grad_norm_ = MethodType(clip_grad_norm_for_sparse_tensor, self.accelerator)
 
     def create_optimizer(self) -> "torch.optim.Optimizer":