public GroupStatListResult getGroupStatistic(String start, int duration)
            throws APIConnectionException, APIRequestException {
        return _reportClient.getGroupStatistic(start, duration);
    }
public GroupStatListResult getGroupStatistic ( String start , int duration ) throws APIConnectionException , APIRequestException { return _reportClient . getGroupStatistic ( start , duration ) ; }
Get group statistic, time unit only supports DAY now.
@param start Format: yyyy-MM-dd
@param duration duration must between 0 and 60
@return {@link GroupStatListResult}
@throws APIConnectionException connect exception
@throws APIRequestException request exception