[CollectionDataContract(
Name = "Customers",
Namespace = "http://schemas.devleap.com/NW/Customers",
ItemName = "Customer")]
public class CustomersList: List<Customers> {
public CustomersList() { }
public CustomersList(IEnumerable<Customers> source): base(source) { }
}

[DataContract(Namespace = "http://schemas.devleap.com/NW/CustomersFilter")]
public class CustomersFilter {
[DataMember(Name = "Country", Order = 0, IsRequired = false)]
public String Country { get; set; }

[DataMember(Name = "Region", Order = 1, IsRequired = false)]
public String Region { get; set; }

}
