code: def test_module_graph(self):
      class Foo(nnx.Module):
          def __init__(self):
              self.a = nnx.Param(1)
              self.sub = self
  
      m = Foo()
  
      state, graphdef = m.split()
      assert len(state) == 1
  
      m2 = graphdef.merge(state)
      assert m2 is m2.sub
  
imports: import dataclasses
  from copy import deepcopy
  from typing import Any, TypeVar
  import jax
  import jax.numpy
  import pytest
  from flax.experimental import nnx
label_desc: Use image node_id 10 for calling the TestModule obj's underlying member method code with example usage: obj.test_module_graph() without return types