code: def _test_fdsp_precision() -> None:
      module = torch.nn.Linear(1, 1)
      device = init_from_env()
      mixed_precision = MixedPrecision(
          param_dtype=torch.float64,
      )
      fsdp_module = prepare_fsdp(
          module, device, FSDPStrategy(mixed_precision=mixed_precision)
      )
      tc = unittest.TestCase()
      tc.assertTrue(isinstance(fsdp_module, FSDP))
      tc.assertEqual(
          fsdp_module.mixed_precision.param_dtype,
          mixed_precision.param_dtype,
      )
  
imports: import unittest
  from unittest.mock import patch
  import torch
  from torch.distributed.fsdp import FullyShardedDataParallel
  from torch.distributed.fsdp.fully_sharded_data_parallel import MixedPrecision
  from torch.nn.parallel import DistributedDataParallel
  from torchtnt.utils.env import init_from_env
  from torchtnt.utils.prepare_module import _is_fsdp_module, DDPStrategy, FSDPStrategy, NOOPStrategy, prepare_ddp, prepare_fsdp, prepare_module, TorchCompileParams
  from torchtnt.utils.test_utils import spawn_multi_process
  from torchtnt.utils.version import is_torch_version_geq_1_13, is_torch_version_geq_2_0
label_desc: Use image node_id 12 for calling the PrepareModelTest obj's underlying member method code with example usage: obj._test_fdsp_precision() without return types