presto-main/src/main/java/io/prestosql/operator/scalar/QuantileDigestFunctions.java/QuantileDigestFunctions/verifyWeight
class QuantileDigestFunctions:    public static long verifyWeight(long weight)
    {
        checkCondition(weight > 0, INVALID_FUNCTION_ARGUMENT, "Percentile weight must be > 0, was %s", weight);
        return weight;
    }