|  |  | 
 |  |  | import com.moral.api.pojo.dto.cityAQI.MonthlyPollutionLevel; | 
 |  |  | import com.moral.api.pojo.dto.cityAQI.PollutionDaysAndProportion; | 
 |  |  | import lombok.Data; | 
 |  |  | import org.springframework.util.ObjectUtils; | 
 |  |  |  | 
 |  |  | import java.util.ArrayList; | 
 |  |  | import java.util.HashMap; | 
 |  |  | 
 |  |  |     List<Map<String, Object>> values; | 
 |  |  |  | 
 |  |  |     public static BarChartOfPollutionLevelVO convert(List<MonthlyPollutionLevel> datas) { | 
 |  |  |         if(ObjectUtils.isEmpty(datas)) | 
 |  |  |             return null; | 
 |  |  |         BarChartOfPollutionLevelVO vo = new BarChartOfPollutionLevelVO(); | 
 |  |  |         List<String> time = new ArrayList<>(); | 
 |  |  |         List<Map<String, Object>> values= new ArrayList<>(); |