code: def _check_pytree(op):
      """Check that the operator is a pytree."""
      data, metadata = op._flatten()
      try:
          assert hash(metadata), "metadata must be hashable"
      except Exception as e:
          raise AssertionError(
              f"metadata output from _flatten must be hashable. Got metadata {metadata}"
          ) from e
      try:
          new_op = type(op)._unflatten(data, metadata)
      except Exception as e:
          message = (
              f"{type(op).__name__}._unflatten must be able to reproduce the original operation from "
              f"{data} and {metadata}. You may need to override either the _unflatten or _flatten method. "
              f"\nFor local testing, try type(op)._unflatten(*op._flatten())"
          )
          raise AssertionError(message) from e
      assert (
          op == new_op
      ), "metadata and data must be able to reproduce the original operation"
  
      try:
          import jax
      except ImportError:
          return
      leaves, struct = jax.tree_util.tree_flatten(op)
      unflattened_op = jax.tree_util.tree_unflatten(struct, leaves)
      assert (
          unflattened_op == op
      ), f"op must be a valid pytree. Got {unflattened_op} instead of {op}."
  
      for d1, d2 in zip(op.data, leaves):
          assert qml.math.allclose(
              d1, d2
          ), f"data must be the terminal leaves of the pytree. Got {d1}, {d2}"
  
file_path: pennylane/pennylane/ops/functions/assert_valid.py
imports: from string import ascii_lowercase
  import copy
  import pickle
  import numpy
  import pennylane
  from pennylane.operation import EigvalsUndefinedError
label_desc: Use image node_id 7 for calling a global function with example usage: _check_pytree(op) without return types