code: def assert_tree_flatten_unflatten(pytree, leaves):
      flat, spec = _tree_flatten(pytree)
      assert flat == leaves
      unflattened = tree_unflatten(flat, spec)
      assert unflattened == pytree
  
imports: import torch
  from lightning.pytorch.utilities._pytree import _tree_flatten, tree_unflatten
  from torch.utils.data import DataLoader, TensorDataset
label_desc: Use image node_id 1 for calling a global function with example usage: assert_tree_flatten_unflatten(pytree, leaves) without return types