code: def test_fast_shift_matrix(self):
      layer = ra._fast_matrix_shift
      x = np.array(
          [
              [
                  [
                      [-3.0, -2.0, -1.0, 0.0],
                      [-3.0, -2.0, -1.0, 0.0],
                      [-3.0, -2.0, -1.0, 0.0],
                      [-3.0, -2.0, -1.0, 0.0],
                  ]
              ]
          ]
      ).astype(np.float32)
  
      y = layer(x)
      self.assertEqual(y.dtype, np.float32)
      self.assertEqual(
          tl.to_list(y),
          [
              [
                  [
                      [0.0, 0.0, -3.0, -2.0],
                      [-1.0, 0.0, 0.0, -3.0],
                      [-2.0, -1.0, 0.0, 0.0],
                      [-3.0, -2.0, -1.0, 0.0],
                  ]
              ]
          ],
      )
  
imports: from absl.testing import absltest
  import numpy
  import trax.layers
  import trax.layers.research.rel_attention
label_desc: Use image node_id 1 for calling the RelAttentionTest obj's underlying member method code with example usage: obj.test_fast_shift_matrix() without return types