The Session type exposes the following members.
Returns the session's customer_key, or null if no customer_key has been set.
The key of this session.(Overrides LRUString, SessionKey.)
Returns the session's market, or null if no market has been set.
The timestamp reported in future notifications and panel requests to the eSales server. This is -1 by default, meaning no time is specified (and hence, the current time on the eSales server will be used as timestamp).