code: def test_dropout_requires_is_training(self):
      mod = mlp.MLP([1, 1], dropout_rate=0.5)
      with self.assertRaisesRegex(
          ValueError, "is_training.* is required"
      ):
          mod(tf.ones([1, 1]))
  
imports: import itertools
  from absl.testing import parameterized
  from sonnet.src import test_utils
  from sonnet.src.nets import mlp
  import tensorflow
label_desc: Use image node_id 18 for calling the MLPTest obj's underlying member method code with example usage: obj.test_dropout_requires_is_training() without return types