@Test
public void testSimpleHash() {

  // Just a simple sanity check.
  final LineSegment3 seg1 = new LineSegment3(Vector3.ZERO, Vector3.UNIT_Y, 2);
  final LineSegment3 seg2 = new LineSegment3(Vector3.ZERO, Vector3.UNIT_Y, 2);
  final LineSegment3 seg3 = new LineSegment3(Vector3.ZERO, Vector3.UNIT_Y, 4);
  assertTrue(seg1.hashCode() == seg2.hashCode());
  assertTrue(seg1.hashCode() != seg3.hashCode());
}