code: def test_layers(self, num_layers):
      mod = mlp.MLP([1] * num_layers)
      self.assertLen(mod.layers, num_layers)
  
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 MLPTest obj's underlying member method code with example usage: obj.test_layers(num_layers) without return types