After the VO class inherits BaseDomain error

/ ** 
 * query returns the safety stock value 
 * 
 * @author GaoBo 
 * @date 8/30/2019 2:55 PM 
 * / 

public  class SafeStockReturn the extends BaseDomain { 

    / ** 
     * Part Number 
     * / 
    Private String materialNo; 

    / ** 
     * Item description 
     * / 
    Private String materialName; 

    / ** 
     * safety stock 
     * / 
    Private Integer safeStock; 

    / ** 
     * Physical inventory 
     * / 
    Private Integer stockQty; 
}

 Returns a list, in addition to BaseDomain paging information and creation time information, demand information are inherited return

/ ** 
 * query returns the safety stock value 
 * 
 * @author GaoBo 
 * @date 8/30/2019 2:55 PM 
 * / 
@Data 
public  class SafeStockReturn { 

    / ** 
     * Part Number 
     * / 
    Private String materialNo; 

    / ** 
     * Item description 
     * / 
    Private String materialName; 

    / ** 
     * safety stock 
     * / 
    Private Integer safeStock; 

    / ** 
     * Physical inventory 
     * / 
    Private Integer stockQty; 
}