code: def testScalarGPU(self):
      indices = [constant_op.constant(0), constant_op.constant(1)]
      data = [constant_op.constant(40.0), constant_op.constant(60.0)]
      for step in -1, 1:
          stitched_t = data_flow_ops.dynamic_stitch(
              indices[::step], data
          )
          stitched_val = self.evaluate(stitched_t)
          self.assertAllEqual([40.0, 60.0][::step], stitched_val)
          # Dimension 0 is max(flatten(indices))+1.
          self.assertEqual([2], stitched_t.get_shape().as_list())
  
imports: import numpy
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import data_flow_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import gradients_impl
  import tensorflow.python.ops.data_flow_grad
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the ParallelDynamicStitchTest obj's underlying member method code with example usage: obj.testScalarGPU() without return types