code: def test_exp_normalized_ntk(self):
      def nngp_fn(cov12, var1, var2):
          prod = jnp.sqrt(var1 * var2)
          return prod * jnp.exp(cov12 / prod - 1)
  
      _, _, kernel_fn = stax.serial(
          stax.Dense(1), stax.Elementwise(nngp_fn=nngp_fn)
      )
  
      _, _, kernel_fn_manual = stax.serial(
          stax.Dense(1), stax.ExpNormalized()
      )
  
      key = random.PRNGKey(1)
      x1 = random.normal(key, (5, 4, 3, 1))
      x2 = random.normal(key, (6, 4, 3, 1))
  
      k = kernel_fn(x1, x2)
      k_manual = kernel_fn_manual(x1, x2)
      self.assertAllClose(k_manual, k)
  
imports: import itertools
  import random
  from absl.testing import absltest
  from jax import config
  from jax import default_backend
  from jax import grad, jacfwd, jacrev, jit, jvp, value_and_grad
  from jax import random
  import jax.numpy
  import neural_tangents
  from neural_tangents import stax
  from neural_tangents._src.empirical import _DEFAULT_TESTING_NTK_IMPLEMENTATION
  from tests import test_utils
label_desc: Use image node_id 11 for calling the ActivationTest obj's underlying member method code with example usage: obj.test_exp_normalized_ntk() and returns: unknown