code: def test_run_seq2seq_fully_sharded_ddp_fp16(self):
      self.run_seq2seq_quick(
          distributed=True,
          extra_args_str="--sharded_ddp zero_dp_2 --fp16",
          predict_with_generate=False,
      )
  
imports: import math
  import os
  import re
  import sys
  import unittest
  from typing import Tuple
  from unittest.mock import patch
  from parameterized import parameterized
  from transformers import AutoModel
  from transformers.testing_utils import CaptureStderr, ExtendSysPath, TestCasePlus, execute_subprocess_async, get_gpu_count, get_torch_dist_unique_port, require_apex, require_bitsandbytes, require_fairscale, require_torch, require_torch_gpu, require_torch_multi_gpu, require_torch_non_multi_gpu, slow
  from transformers.trainer_callback import TrainerState
  from transformers.trainer_utils import set_seed
label_desc: Use image node_id 8 for calling the TestTrainerExt obj's underlying member method code with example usage: obj.test_run_seq2seq_fully_sharded_ddp_fp16() without return types