code: def testGradientsLastDim(self):
      # Test both positive and negative concat axis.
      # -1 and 2 correspond to the same axis for 3-dimensional tensors.
      for axis in [-1, 2]:
          with test_util.use_gpu():
              inp = []
              inp_tensors = []
              for x in [1, 2, 6]:
                  shape = [10, 2, x]
                  t = np.random.rand(*shape).astype("f")
                  inp.append(t)
                  inp_tensors.append(
                      constant_op.constant(
                          t.flatten(), shape=shape, dtype=dtypes.float32
                      )
                  )
              c = array_ops.concat(inp_tensors, 2)
              output_shape = [10, 2, 9]
              grad_inp = np.random.rand(*output_shape).astype("f")
              grad_tensor = constant_op.constant(
                  grad_inp.flatten(), shape=output_shape
              )
              grad = gradients_impl.gradients(
                  [c], inp_tensors, [grad_tensor]
              )
              concated_grad = array_ops.concat(grad, axis)
              result = self.evaluate(concated_grad)
  
      self.assertAllEqual(result, grad_inp)
  
imports: import numpy
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors_impl
  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 gen_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 import variables
  from tensorflow.python.platform import test
label_desc: Use image node_id 16 for calling the ConcatOpTest obj's underlying member method code with example usage: obj.testGradientsLastDim() without return types