Informs the extension that its class helper is going away.
[Visual Basic .NET] Public Sub Shutdown ( _ )
[C#] public void Shutdown ( );
[C++] HRESULT Shutdown( void );
Shutdown is called when the extension's class is cleared from the client's memory, or when the extension is removed from the class. Note that if a class is deleted from a geodatabase, it may remain in memory, so this should not be relied upon for behavior that should be triggered by a class' deletion.