docstr: Tests that ``apply()`` modifies parameter values in-place on a
  non-FSDP-root nested FSDP-wrapped model.
docstr_tok: ["Tests","that","``","apply","(",")","``","modifies","parameter","values","in-place","on","a","non-FSDP-root","nested","FSDP-wrapped","model","."]
code: def test_nested_module_apply(self):
      """Tests that ``apply()`` modifies parameter values in-place on a
      non-FSDP-root nested FSDP-wrapped model."""
      nested_wrapped_module = NestedWrappedModule.init(
          self.process_group,
          FSDPInitMode.RECURSIVE,
          CUDAInitMode.CUDA_AFTER,
      )
      self._check_apply(nested_wrapped_module)
  
file_path: pytorch/test/distributed/fsdp/test_fsdp_apply.py
imports: import sys
  import torch
  import torch.distributed
  import torch.nn
  from torch.distributed.fsdp import FullyShardedDataParallel
  from torch.testing._internal.common_distributed import skip_if_lt_x_gpu
  from torch.testing._internal.common_fsdp import CUDAInitMode, FSDPInitMode, FSDPTest, NestedWrappedModule, TransformerWithSharedParams
  from torch.testing._internal.common_utils import run_tests, TEST_WITH_DEV_DBG_ASAN
label_desc: Use image node_id 5 for calling the TestApply obj's underlying member method code with example usage: obj.test_nested_module_apply() without return types