Which is a valid value for the enum EmptyRoleSemantic in Javax.servlet.annotation.ServletSecurity?

The following example is for all HTTP methods except TRACE, the element requires membership in ALL ROLE, and for TRACE, all access is denied.

@WebServlet (name=”Example”, urlPatterns={“/Example”})
@ServletSecurity(value = @HttpConstraint(rolesAllowed = “ALL ROLE”),
httpMethodConstraints = @HttpMethodConstraint(value=”TRACE”,
emptyRoleSemantic = EmptyRoleSemantic.DENY))
public class Example extends HttpServlet {
……
}

http://www.ibm.com/support/knowledgecenter/SSAW57_8.5.5/com.ibm.websphere.nd.doc/ae/csec_annotations.html