code: def testDocstringExample(self):
      arrays = _NumpyState()
      checkpoint = util.Checkpoint(numpy_arrays=arrays)
      arrays.x = numpy.zeros([3, 4])
      save_path = checkpoint.save(
          os.path.join(self.get_temp_dir(), "ckpt")
      )
      arrays.x[1, 1] = 4.0
      checkpoint.restore(save_path)
      self.assertAllEqual(numpy.zeros([3, 4]), arrays.x)
  
      second_checkpoint = util.Checkpoint(numpy_arrays=_NumpyState())
      second_checkpoint.restore(save_path)
      self.assertAllEqual(
          numpy.zeros([3, 4]), second_checkpoint.numpy_arrays.x
      )
  
imports: import io
  import os
  import numpy
  from tensorflow.python.checkpoint import checkpoint
  from tensorflow.python.client import session
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.module import module
  from tensorflow.python.platform import test
  from tensorflow.python.trackable import python_state
label_desc: Use image node_id 4 for calling the NumpyStateTests obj's underlying member method code with example usage: obj.testDocstringExample() without return types