public void testCheckPositive_zeroBigInteger() {
    assertThrows(
        IllegalArgumentException.class,
        () -> MathPreconditions.checkPositive("BigInteger", BigInteger.ZERO));
  }

  public void testCheckPositive_positiveBigInteger() {
    MathPreconditions.checkPositive("BigInteger", BigInteger.ONE);
  }

  public void testCheckPositive_negativeBigInteger() {
    assertThrows(
        IllegalArgumentException.class,