### Question:
Exercise4 { static Integer minimum(final List<Integer> list) { if (list.isEmpty()) throw new IllegalArgumentException("list is empty"); throw new UnsupportedOperationException("Exercise 4 minimum is missing!"); }    }### Answer:
@Test public void shouldFindMinimum() { final List<Integer> list = asList(1, 2, 3, 4); final Integer expected = 1; final Integer actual = Exercise4.minimum(list); assertEquals(expected, actual); }