ISSUE 95: Scenarios for SCA conversations

On Monday's call I took an action item to find scenarios that
have previously been put forward for SCA conversations so that
we could use these to compare and contrast the proposals from
Jim and myself.

As I suspected, most of the scenarios that we have discussed were
created to illustrate callbacks rather than conversations.  However,
these often involve stateful interactions, so they might be relevant.

I have been though all the examples I could find and they are
all variations on the shopping cart / order entry theme.  The
following interface is a synthesis of various different examples.

public interface Order {

     String create();
         // returns an orderID for use in subsequent calls
         // could pass some information, such as customer info
         // for implicit correlation, this method might not be needed

     void add(String orderID, String itemID, int quantity);
         // the orderID might be explicit as shown here, or implicit

     void remove(String orderID, String itemID, int quantity)
             throws ItemNotFoundException;
         // throws exception if specified number of items not in the order
         // the orderID might be explicit as shown here, or implicit

     void submit(String orderID) throws EmptyCartException;
         // throws exception if cart is empty
         // the orderID might be explicit as shown here, or implicit
}

Can anyone suggest additional scenarios where SCA conversations
would be used?  Jim has mentioned that he has some.

   Simon