[-0.0614, -0.7344, -1.3164, -0.7648, -1.4024,  0.0000]])
      >>> torch.tril(b, diagonal=-1)
      tensor([[ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
              [ 0.4785,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
              [ 1.1502,  3.2716,  0.0000,  0.0000,  0.0000,  0.0000],
              [-0.0614, -0.7344, -1.3164,  0.0000,  0.0000,  0.0000]])