docstr: Tests ragged_stack with a single tensor input.
  
  Usually, we pass a list of values in for rt_inputs.  However, you can
  also pass in a single value (as with tf.stack), in which case it is
  equivalent to expand_dims(axis=0).  This test exercises that path.
code: def testSingleTensorInput(self):
      """Tests ragged_stack with a single tensor input.
  
      Usually, we pass a list of values in for rt_inputs.  However, you can
      also pass in a single value (as with tf.stack), in which case it is
      equivalent to expand_dims(axis=0).  This test exercises that path.
      """
      rt_inputs = ragged_factory_ops.constant([[1, 2], [3, 4]])
      stacked = ragged_concat_ops.stack(rt_inputs, 0)
      self.assertAllEqual(stacked, [[[1, 2], [3, 4]]])
  
file_path: tensorflow/tensorflow/python/ops/ragged/ragged_stack_op_test.py
imports: from absl.testing import parameterized
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops.ragged import ragged_concat_ops
  from tensorflow.python.ops.ragged import ragged_factory_ops
  from tensorflow.python.platform import googletest
label_desc: Use image node_id 3 for calling the RaggedStackOpTest obj's underlying member method code with example usage: obj.testSingleTensorInput() without return types