The cardinality of the attribute. Valid Values: 
- ONE(1) : Single value required
- ZERO_OR_ONE(0..1) : Up to one value can be supplied
- ZERO_OR_MORE(0..*) : Optional. Multiple values are allowed
- ONE_OR_MORE(1..*0) : Required. Multiple values are allowed
 Declaration Syntax
 Declaration Syntax| C# | 
public string Cardinality { get; set; }