How does bounds.Expand() work ?

I’m a bit confused as to how bounds.Expand() works:

    Bounds bounds = collider.bounds;             
    Debug.Log("Before " + bounds.min.x);       // -0.5
    Debug.Log("Before " + bounds.size);        // (1.0, 1.0, 0.0) 

    bounds.Expand(0.015f * -2.0f);

    Debug.Log("After " + bounds.min.x);        // -0.485
    Debug.Log("After " + bounds.size);         // (1.0, 1.0, 0.0)

The documentation says “Expand the bounds by increasing its size by amount along each side.”, but the snippet above seems to show that size is not affected and only bounds.min is changed ?

All of them are changed. Bounds.ToString() returns the floating numbers rounded to the nearest int.