presto-main/src/main/java/io/prestosql/operator/scalar/UrlFunctions.java/UrlFunctions/urlDecode
class UrlFunctions:    @Description("unescape a URL-encoded string")
    @ScalarFunction
    @LiteralParameters("x")
    @SqlType("varchar(x)")
    public static Slice urlDecode(@SqlType("varchar(x)") Slice value)
    {
        return decodeUrl(value.toStringUtf8());
    }