code: @Beta
    public static int ceilingPowerOfTwo(int x) {
      checkPositive("x", x);
      if (x > MAX_SIGNED_POWER_OF_TWO) {
        throw new ArithmeticException("ceilingPowerOfTwo(" + x + ") not representable as an int");
      }
      return 1 << -Integer.numberOfLeadingZeros(x - 1);
    }
docs: Returns the smallest power of two greater than or equal to {@code x}. This is equivalent to
  {@code checkedPow(2, log2(x, CEILING))}.
  
  @throws IllegalArgumentException if {@code x <= 0}
  @throws ArithmeticException of the next-higher power of two is not representable as an {@code
  int}, i.e. when {@code x > 2^30}
  @since 20.0