static boolean sum2one(final double[] probabilities) {
		final double sum = probabilities.length > 0
			? DoubleAdder.sum(probabilities)
			: 1.0;
		return abs(ulpDistance(sum, 1.0)) < MAX_ULP_DISTANCE;
	}
Check if the given probabilities sum to one.

@param probabilities the probabilities to check.
@return {@code true} if the sum of the probabilities is within the error
        range, {@code false} otherwise.
jenetics/src/main/java/io/jenetics/ProbabilitySelector.java