code: def test_update(self):
      init_fn, _ = hk.without_apply_rng(hk.transform(dummy_network))
      params = init_fn(jax.random.PRNGKey(1), jnp.zeros(shape=(1, 32)))
      variable_source = fakes.VariableSource(params)
      variable_client = variable_utils.VariableClient(
          variable_source, key="policy"
      )
      variable_client.update_and_wait()
      tree.map_structure(
          np.testing.assert_array_equal, variable_client.params, params
      )
  
file_path: acme/acme/jax/variable_utils_test.py
imports: from acme.jax import variable_utils
  from acme.testing import fakes
  import haiku
  import jax
  import jax.numpy
  import numpy
  import tree
  from absl.testing import absltest
label_desc: Use image node_id 1 for calling the VariableClientTest obj's underlying member method code with example usage: obj.test_update() without return types