[reSIProcate] InMemoryRegistrationDatabase expiry question

[Daniel Pocock]

I've just been looking at InMemoryRegistrationDatabase and 
RegistrationPersistenceManager

What is the proper behaviour for isAorRegistered() when all the contacts 
are expired?

If the aor is known, but all contacts are expired, should 
isAorRegistered() return false?  I believe this should be the case, but 
it is not stated in either interface.

I am about to update the class InMemoryRegistrationDatabase so that it 
will do the following:

- isAorRegistered() will only return true if there is at least one 
non-expired contact

- getContacts() will only return non-expired contacts

Should I also update RegistrationPersistenceManager with comments 
incorporating those two statements, or would that be too restrictive 
upon other possible implementations of RegistrationPersistenceManager? 

At the very least, I would like to put some comment in 
RegistrationPersistenceManager.hxx to state whether or not the caller 
has to check the expiry of the return values.