revert some format changes

Signed-off-by: HuiyingLi <willwin.lee@gmail.com>

Author: HuiyingLi

verl/workers/engine/torchtitan/transformer_impl.py

@@ -26,8 +26,6 @@
 import torch.distributed
 from tensordict import TensorDict
 from torch.distributed.tensor import DTensor
-
-import verl.utils.torch_functional as verl_F
 from torchtitan.config.job_config import (
     Checkpoint,
     Compile,
@@ -42,6 +40,8 @@
 from torchtitan.distributed.context_parallel import prepare_context_parallel_input
 from torchtitan.distributed.parallel_dims import ParallelDims
 from torchtitan.train import Trainer
+
+import verl.utils.torch_functional as verl_F
 from verl.trainer.config import CheckpointConfig
 from verl.utils import tensordict_utils as tu
 from verl.utils.dataset.dataset_utils import DatasetPadMode

verl/workers/engine/torchtitan/utils.py

@@ -17,7 +17,6 @@
 import torch.nn as nn
 from torch.distributed._composable.fsdp import FSDPModule
 from torch.nn.attention.flex_attention import _mask_mod_signature, and_masks
-
 from torchtitan.models.attention import VarlenMetadata, create_attention_mask, get_causal_mask_mod
 from torchtitan.protocols.model import AttentionMasksType