Option 2 – Model as First Class Concept
Introduce an “Attribute” concept to wsdl:interface
Similar to attribute in CORBA IDL
Core idea:
Elements of publicly available state are  modeled using XML
Schema element
State of a Web service instance is modeled “logically” as an
XML instance document
Define operations: get, set, query, [subscribe]
Elements of state are modeled with the interface definition as
attributes
Use attributes to convey state and meta-data of the service
Client proxy generators can still generate type-specific
getters/setters (if they want)