void InitializationData()
        {
            SingleSource.Add("Asia");
            SingleSource.Add("Europe");
            SingleSource.Add("America");
            SingleSource.Add("Africa");
            SingleSource.Add("Oceania");

            ObservableCollection <PropertyModel> enterprise = new ObservableCollection <PropertyModel>();

            enterprise.Add(new PropertyModel {
                Id = 1, Name = "Alibaba"
            });
            enterprise.Add(new PropertyModel {
                Id = 2, Name = "Tencent"
            });
            enterprise.Add(new PropertyModel {
                Id = 3, Name = "Baidu"
            });
            enterprise.Add(new PropertyModel {
                Id = 4, Name = "Huawei"
            });
            enterprise.Add(new PropertyModel {
                Id = 5, Name = "Wangyi"
            });

            ObservableCollection <PropertyModel> countries = new ObservableCollection <PropertyModel>();

            countries.Add(new PropertyModel {
                Id = 1, Name = "China"
            });
            countries.Add(new PropertyModel {
                Id = 2, Name = "USA"
            });
            countries.Add(new PropertyModel {
                Id = 3, Name = "Japan"
            });
            countries.Add(new PropertyModel {
                Id = 4, Name = "South Korea"
            });
            countries.Add(new PropertyModel {
                Id = 5, Name = "Russia"
            });
            countries.Add(new PropertyModel {
                Id = 6, Name = "French"
            });
            countries.Add(new PropertyModel {
                Id = 7, Name = "Germany"
            });

            TwoSource.Add(new GroupModel {
                GroupName = "enterprise", Property = enterprise
            });
            TwoSource.Add(new GroupModel {
                GroupName = "countries", Property = countries
            });
        }