code: def __call__(self, x):
      self.count += 1
      return x
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  from haiku._src import test_utils
  from haiku._src.nets import mlp
  import jax
  import jax.numpy
label_desc: Use image node_id 2 for calling the CountingActivation obj's underlying member method code with example usage: obj.__call__(x) and returns: x