code: def setup_class(cls):
      if not torch.cuda.is_available():
          return
      GPUS = 1
      TP_SIZE = GPUS
      PP_SIZE = 1
      MB_SIZE = 4
      GB_SIZE = 8
      SEED = 1234
      trainer = Trainer(
          strategy=NLPDDPStrategy(),
          devices=GPUS,
          accelerator="gpu",
          num_nodes=1,
          logger=None,
      )
  
      initialize_model_parallel_for_nemo(
          world_size=trainer.world_size,
          global_rank=trainer.global_rank,
          local_rank=trainer.local_rank,
          tensor_model_parallel_size=TP_SIZE,
          pipeline_model_parallel_size=PP_SIZE,
          micro_batch_size=MB_SIZE,
          global_batch_size=GB_SIZE,
          seed=SEED,
          apex_transformer_log_level=30,
      )
  
      def dummy():
          return
  
      if trainer.strategy.launcher is not None:
          trainer.strategy.launcher.launch(dummy, trainer=trainer)
      trainer.strategy.setup_environment()
      torch.distributed.barrier()
  
file_path: NeMo/tests/collections/nlp/test_retrieval_module_inference.py
imports: import pytest
  import torch
  import torch.nn.functional
  from einops import rearrange
  from pytorch_lightning.trainer.trainer import Trainer
  from nemo.collections.nlp.modules.common.megatron.attention import ParallelChunkedCrossAttention
  from nemo.collections.nlp.modules.common.megatron.layer_type import LayerType
  from nemo.collections.nlp.modules.common.megatron.megatron_init import initialize_model_parallel_for_nemo
  from nemo.collections.nlp.modules.common.megatron.position_embedding import RotaryEmbedding
  from nemo.collections.nlp.modules.common.megatron.retrieval_token_level_encoder_decoder import MegatronRetrievalTokenLevelEncoderDecoderModule
  from nemo.collections.nlp.modules.common.megatron.retrieval_transformer import MegatronRetrievalTransformerDecoderModule, MegatronRetrievalTransformerEncoderModule
  from nemo.collections.nlp.modules.common.megatron.utils import build_attention_mask_3d, init_method_normal, scaled_init_method_normal
  from nemo.collections.nlp.parts.nlp_overrides import NLPDDPStrategy
label_desc: Use image node_id 1 for calling the TestRetrievalModuleInference obj's underlying member method code with example usage: obj.setup_class(cls) without return types