presto-main/src/main/java/io/prestosql/operator/scalar/MathFunctions.java/MathFunctions/absShort
class MathFunctions:        @LiteralParameters({"p", "s"})
        @SqlType("decimal(p, s)")
        public static long absShort(@SqlType("decimal(p, s)") long arg)
        {
            return arg > 0 ? arg : -arg;
        }