code: def test_lower_bound():
      x = torch.rand(16, requires_grad=True)
  
      bound = torch.rand(1)
  
      torch.testing.assert_close(
          lower_bound(x, bound),
          torch.max(x, bound),
      )
  
      bound = torch.rand(1)
  
      y = lower_bound(x, bound)
  
      torch.testing.assert_close(
          y,
          torch.max(x, bound),
      )
  
      y.backward(x)
  
      assert x.grad is not None
  
      torch.testing.assert_close(
          x.grad,
          (x >= bound) * x,
      )
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_lower_bound() without return types