code: def test_simple_case_nchwvar(self):
      layer = group_norm.GroupNorm(
          groups=5,
          create_scale=True,
          create_offset=True,
          scale_init=initializers.Constant(0.5),
          offset_init=initializers.Constant(2.0),
          data_format="NCHW",
      )
  
      inputs = jnp.ones([2, 10, 3, 3])
  
      outputs = layer(inputs)
      for x in np.nditer(outputs):
          self.assertEqual(x, 2.0)
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from haiku._src import group_norm
  from haiku._src import initializers
  from haiku._src import test_utils
  import jax.numpy
  import numpy
label_desc: Use image node_id 3 for calling the GroupNormTest obj's underlying member method code with example usage: obj.test_simple_case_nchwvar() without return types