code: def testStack(self):
      with self.session(), self.test_scope():
          l = list_ops.empty_tensor_list(
              element_dtype=dtypes.float32,
              element_shape=[],
              max_num_elements=2,
          )
          l = list_ops.tensor_list_push_back(
              l, constant_op.constant(1.0)
          )
          e = list_ops.tensor_list_get_item(
              l, 0, element_dtype=dtypes.float32
          )
          self.assertAllEqual(e, 1.0)
          l = list_ops.tensor_list_push_back(
              l, constant_op.constant(2.0)
          )
          t = list_ops.tensor_list_stack(
              l, element_dtype=dtypes.float32
          )
          self.assertAllEqual(t.shape.as_list(), [None])
          self.assertAllEqual(t, [1.0, 2.0])
  
imports: import os
  from absl.testing import parameterized
  import numpy
  from tensorflow.compiler.tests import xla_test
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import list_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 14 for calling the ListOpsTest obj's underlying member method code with example usage: obj.testStack() without return types