public GroupingOperation addOrderBy(List<GroupingExpression> list) {
        for (GroupingExpression exp : list) {
            addOrderBy(exp);
        }
        return this;
    }
Convenience method to call {@link #addOrderBy(GroupingExpression)} for each element in the given list.

@param list the list of expressions to add
@return this, to allow chaining
container-search/src/main/java/com/yahoo/search/grouping/request/GroupingOperation.java