code: def test_deref_number_of_fields(self):
      r1 = nnx.Variable(1)
      r2 = nnx.Variable(2)
      v1 = 3
      m = nnx.Dict(
          {
              "a": nnx.Sequence([r1, r2, v1]),
              "b": nnx.Dict({"c": r1, "d": r2}),
          }
      )
  
      p, graphdef = m.split()
      assert len(p.flat_state()) == 2
      assert len(jax.tree_util.tree_leaves(p)) == 2
  
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 14 for calling the TestModule obj's underlying member method code with example usage: obj.test_deref_number_of_fields() without return types