long q = BigInteger.probablePrime(bits, rand).longValue();
        assertFalse(LongMath.isPrime(p * q));
      }
    }
  }

  @GwtIncompatible // isPrime is GWT-incompatible
  public void testIsPrimeThrowsOnNegative() {
    try {
      LongMath.isPrime(-1);
      fail("Expected IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }
  }

        long q = BigInteger.probablePrime(bits, rand).longValue();
        assertFalse(LongMath.isPrime(p * q));
      }
    }
  }

  @GwtIncompatible // isPrime is GWT-incompatible
  public void testIsPrimeThrowsOnNegative() {
    try {
      LongMath.isPrime(-1);
      fail("Expected IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }
  }