code: def testRuns(self):
      with mock.patch.object(dataset, "load", new=fake_mnist_data):
          train.train(
              batch_size=1,
              learning_rate=0.1,
              num_training_iters=10,
              validation_steps=5,
          )
          train.train(
              batch_size=2,
              learning_rate=0.1,
              num_training_iters=5,
              validation_steps=2,
          )
          train.train(
              batch_size=10,
              learning_rate=0.1,
              num_training_iters=1,
              validation_steps=1,
          )
  
file_path: trax/trax/tf_numpy/examples/mnist/train_test.py
imports: import mock
  import numpy
  import tensorflow.compat.v2
  from trax.tf_numpy.examples.mnist import dataset
  from trax.tf_numpy.examples.mnist import train
label_desc: Use image node_id 1 for calling the TFNumpyMnistExampleTest obj's underlying member method code with example usage: obj.testRuns() without return types