code: def __init__(
      self, leaf_module_names: Optional[List[str]] = None
  ) -> None:
      super().__init__()
      self._leaf_module_names = leaf_module_names or []
  
file_path: torchrec/torchrec/modules/tests/test_mc_embedding_modules.py
imports: import unittest
  from copy import deepcopy
  from typing import cast, Dict, List, Optional
  import torch
  from torchrec.modules.embedding_configs import EmbeddingBagConfig, EmbeddingConfig
  from torchrec.modules.embedding_modules import EmbeddingBagCollection, EmbeddingCollection
  from torchrec.modules.mc_embedding_modules import ManagedCollisionEmbeddingBagCollection, ManagedCollisionEmbeddingCollection
  from torchrec.modules.mc_modules import DistanceLFU_EvictionPolicy, ManagedCollisionCollection, ManagedCollisionModule, MCHManagedCollisionModule
  from torchrec.sparse.jagged_tensor import KeyedJaggedTensor, KeyedTensor
label_desc: Use image node_id 1 to create a new Tracer object from inherited base classes: torch.fx with example: obj = Tracer(leaf_module_names)