class_docstr: Common tests for Sonnet optimizers.
code: def testNoneUpdate(self):
      parameters = [tf.Variable(1.0), tf.Variable(2.0)]
      updates = [None, tf.constant(3.0)]
      optimizer = self.make_optimizer()
      optimizer.apply(updates, parameters)
      self.assertAllClose(1.0, parameters[0].numpy())
  
imports: import itertools
  from absl.testing import parameterized
  import numpy
  from sonnet.src import base
  from sonnet.src import test_utils
  import tensorflow
  import tree
label_desc: Use image node_id 2 for calling the OptimizerTestBase obj's underlying member method code with example usage: obj.testNoneUpdate() without return types