code: def test_trainable(self, trainable):
      with hk.variables():
          v = tf.Variable(1.0, trainable=trainable)
      if trainable is None:
          self.assertTrue(v.trainable)
      else:
          self.assertEqual(v.trainable, trainable)
  
imports: from absl.testing import parameterized
  import sonnet
  from sonnet.src import test_utils
  from sonnet.src.functional import haiku
  import tensorflow
  import tree
label_desc: Use image node_id 2 for calling the TensorVariableTest obj's underlying member method code with example usage: obj.test_trainable(trainable) without return types