presto-main/src/main/java/io/prestosql/operator/scalar/MathFunctions.java/MathFunctions/betaCdf
class MathFunctions:    @Description("Beta cdf given the a, b parameters and value")
    @ScalarFunction
    @SqlType(StandardTypes.DOUBLE)
    public static double betaCdf(
            @SqlType(StandardTypes.DOUBLE) double a,
            @SqlType(StandardTypes.DOUBLE) double b,
            @SqlType(StandardTypes.DOUBLE) double value)
    {
        checkCondition(value >= 0 && value <= 1, INVALID_FUNCTION_ARGUMENT, "value must be 0 >= v >= 1");
        checkCondition(a > 0 && b > 0, INVALID_FUNCTION_ARGUMENT, "a, b must be > 0");
        BetaDistribution distribution = new BetaDistribution(null, a, b, BetaDistribution.DEFAULT_INVERSE_ABSOLUTE_ACCURACY);
        return distribution.cumulativeProbability(value);
    }