public static String getLevelDesc(int level) {
        if (level <= 0) {
            return "single hit";
        } else if (level == 1) {
            return "single group";
        } else {
            return "list of ".repeat(level - 1) + "groups";
        }
    }
Returns a description of the given level. This allows for more descriptive errors being passed back to the user.

@param level The level to describe.
@return A description of the given level.
container-search/src/main/java/com/yahoo/search/grouping/request/GroupingOperation.java