### Question:
CollisionGroup extends NameableAbstract { public static boolean same(String groupA, String groupB) { final boolean result; if (groupA != null && groupB != null) { result = groupA.equals(groupB); } else if (groupA == null && groupB == null) { result = true; } else { result = false; } return result; } CollisionGroup(String name, Collection<CollisionFormula> formulas); static boolean same(String groupA, String groupB); Collection<CollisionFormula> getFormulas(); @Override String toString();  }### Answer:
@Test void testSame() { assertTrue(CollisionGroup.same(null, null)); assertTrue(CollisionGroup.same("a", "a")); assertFalse(CollisionGroup.same(null, "a")); assertFalse(CollisionGroup.same("a", null)); assertFalse(CollisionGroup.same("a", "b")); }