how do i get my testNormalize to throw an exception? what is the junit code for it and rhe class code if needed

// Test for normalize @Test public void testNormalize() { Vector3D v1 = new Vector3D( x: 20, y: 10, z 25); Vector3D v2 = new Vector3D( x: 15, y: 25, z 30); Assert.assertEquals( expected: "(0.60,0.30,0.75)", v1.normalize().toString(); Assert.assertEquals( expected: "(0.36, 0.60,0.72)", V2.normalize().toString()