code: def _testXent2D(
      self,
      np_labels,
      np_logits,
      with_placeholders=False,
      expected_gradient=None,
  ):
      np_loss, np_gradient = self._npXent(
          labels=np_labels, logits=np_logits
      )
      if expected_gradient is not None:
          np_gradient = expected_gradient
      with self.cached_session() as sess:
          if with_placeholders:
              logits_placeholder = array_ops.placeholder(
                  np_logits.dtype
              )
              labels_placeholder = array_ops.placeholder(
                  np_labels.dtype
              )
              loss, gradient = self._opFwdBwd(
                  labels_placeholder, logits_placeholder
              )
              tf_loss, tf_gradient = sess.run(
                  [loss, gradient],
                  feed_dict={
                      labels_placeholder: np_labels,
                      logits_placeholder: np_logits,
                  },
              )
          else:
              loss, gradient = self._opFwdBwd(np_labels, np_logits)
              tf_loss, tf_gradient = self.evaluate([loss, gradient])
      self.assertAllCloseAccordingToType(
          np_loss, tf_loss, half_rtol=1e-2
      )
      self.assertAllCloseAccordingToType(np_gradient, tf_gradient)
  
imports: import numpy
  from tensorflow.python.eager import backprop
  from tensorflow.python.framework import config
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gradient_checker
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.ops.nn_grad import _SoftmaxCrossEntropyWithLogitsGrad
  from tensorflow.python.platform import test
label_desc: Use image node_id 3 for calling the XentOpTestBase obj's underlying member method code with example usage: obj._testXent2D(np_labels, np_logits, with_placeholders, expected_gradient) without return types