### Question:
IntegerUtil { public static int safeSignum(final Integer v) { if (v != null) { return Integer.signum(v.intValue()); } return 0; } private  IntegerUtil(); static boolean isNotZero(final Integer value); static boolean isZero(final Integer value); static boolean isNullOrZero(final Integer value); static boolean isSameValue(final Integer val1, final Integer val2); static boolean isNotSameValue(final Integer val1, final Integer val2); static Integer safeAdd(final Integer v1, final Integer v2); static int safeSignum(final Integer v); static int safeCompare(final Integer id, final Integer id2); static Integer assign(final Integer value, final Integer defaultValueIfNull); static boolean isNotZeroOrNegative(final Integer id);  }### Answer:
@Test public void testSafeSignum() { assertThat(safeSignum(null)).isEqualTo(0); assertThat(safeSignum(0)).isEqualTo(0); assertThat(safeSignum(100)).isEqualTo(1); assertThat(safeSignum(-100)).isEqualTo(-1); }