}
  }

  public void testModZeroModulusFails() {
    for (int x : ALL_INTEGER_CANDIDATES) {
      assertThrows(ArithmeticException.class, () -> IntMath.mod(x, 0));
    }
  }

  public void testGCD() {
    for (int a : POSITIVE_INTEGER_CANDIDATES) {
      for (int b : POSITIVE_INTEGER_CANDIDATES) {
        assertEquals(valueOf(a).gcd(valueOf(b)), valueOf(IntMath.gcd(a, b)));
      }
    }
  }