public static <T extends Number> WithinGroup<T> percentileDisc(T arg) {
        if (arg.doubleValue() < 0.0 || arg.doubleValue() > 1.0) {
            throw new IllegalArgumentException("The percentile value should be a number between 0 and 1");
        }
        return percentileDisc(ConstantImpl.create(arg));
    }
PERCENTILE_DISC is an inverse distribution function that assumes a discrete distribution model.
It takes a percentile value and a sort specification and returns an element from the set.
Nulls are ignored in the calculation.

<p>This function takes as an argument any numeric datatype or any nonnumeric datatype that can be
implicitly converted to a numeric datatype. The function returns the same datatype as the numeric
datatype of the argument.</p>

@param arg argument
@return percentile_disc(arg)
querydsl-sql/src/main/java/com/querydsl/sql/SQLExpressions.java