assertEquals(
        "The mean of x and y should equal the mean of y and x", expectedMean, LongMath.mean(y, x));
  }

  /**
   * Computes the mean in a way that is obvious and resilient to overflow by using BigInteger
   * arithmetic.
   */
  private static long computeMeanSafely(long x, long y) {
    BigInteger bigX = BigInteger.valueOf(x);
    BigInteger bigY = BigInteger.valueOf(y);

    assertEquals(
        "The mean of x and y should equal the mean of y and x", expectedMean, LongMath.mean(y, x));
  }

  /**
   * Computes the mean in a way that is obvious and resilient to overflow by using BigInteger
   * arithmetic.
   */
  private static long computeMeanSafely(long x, long y) {
    BigInteger bigX = BigInteger.valueOf(x);
    BigInteger bigY = BigInteger.valueOf(y);