Called by Lightstreamer Kernel through the Remote Server to notify the Metadata Adapter that a push Session has been closed. 

This method is called by the Server asynchronously and does not consume a pooled thread on the Server. As a consequence, it is not guaranteed that no more calls related with this sessionID, like notifyNewTables, notifyTablesClose, and getItems can occur after its invocation on parallel threads. Accepting them would have no effect. However, if the method may have side-effects on the Adapter, like notifyUserMessage, the Adapter is responsible for checking if the session is still valid. 

void NotifySessionClose(string sessionID);

void NotifySessionClose(string sessionID);

Function NotifySessionClose(sessionID As string) As void