code: def test_concat_with_padding2(self):
      vec_e = np.array(
          [
              [
                  [7, 5, 2, 8, 8, 8, 6, 7],
                  [8, 2, 6, 2, 1, 1, 4, 2],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
              ],
              [
                  [4, 3, 1, 7, 5, 6, 2, 1],
                  [6, 9, 9, 4, 1, 3, 2, 1],
                  [3, 8, 2, 4, 7, 9, 4, 1],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
              ],
          ]
      )
  
      # vec_e[:,:,0] != 0
      mask_e = np.array(
          [
              [True, True, False, False, False, False],
              [True, True, True, False, False, False],
          ]
      )
  
      vec_d = np.array(
          [
              [
                  [4, 7, 7, 4, 8, 9, 9, 9],
                  [6, 8, 2, 9, 3, 6, 6, 8],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
              ],
              [
                  [3, 7, 5, 6, 2, 9, 3, 1],
                  [4, 7, 3, 2, 1, 1, 1, 6],
                  [0, 0, 0, 0, 0, 0, 0, 0],
                  [0, 0, 0, 0, 0, 0, 0, 0],
              ],
          ]
      )
  
      layer = transformer2.ConcatWithPadding2(mode="train")
      inp = (vec_e, vec_e, vec_d, mask_e, vec_e, vec_d)
      layer.init(shapes.signature(inp))
      y1, y2, _, _ = layer(inp)
  
      np.testing.assert_equal(
          y1,
          np.array(
              [
                  [
                      [7, 5, 2, 8, 8, 8, 6, 7],
                      [8, 2, 6, 2, 1, 1, 4, 2],
                      [4, 7, 7, 4, 8, 9, 9, 9],
                      [6, 8, 2, 9, 3, 6, 6, 8],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                  ],
                  [
                      [4, 3, 1, 7, 5, 6, 2, 1],
                      [6, 9, 9, 4, 1, 3, 2, 1],
                      [3, 8, 2, 4, 7, 9, 4, 1],
                      [3, 7, 5, 6, 2, 9, 3, 1],
                      [4, 7, 3, 2, 1, 1, 1, 6],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                  ],
              ]
          ),
      )
      np.testing.assert_equal(
          y2,
          np.array(
              [
                  [
                      [7, 5, 2, 8, 8, 8, 6, 7],
                      [8, 2, 6, 2, 1, 1, 4, 2],
                      [4, 7, 7, 4, 8, 9, 9, 9],
                      [6, 8, 2, 9, 3, 6, 6, 8],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                  ],
                  [
                      [4, 3, 1, 7, 5, 6, 2, 1],
                      [6, 9, 9, 4, 1, 3, 2, 1],
                      [3, 8, 2, 4, 7, 9, 4, 1],
                      [3, 7, 5, 6, 2, 9, 3, 1],
                      [4, 7, 3, 2, 1, 1, 1, 6],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                      [0, 0, 0, 0, 0, 0, 0, 0],
                  ],
              ]
          ),
      )
  
file_path: trax/trax/models/research/transformer2_test.py
imports: from absl.testing import absltest
  import numpy
  from trax import shapes
  from trax.models.research import transformer2
label_desc: Use image node_id 3 for calling the Transformer2Test obj's underlying member method code with example usage: obj.test_concat_with_padding2() without return types