Call PreventDestruction if the WebSnap application should not free the Web module instance when the current HTTP request message has been fully processed. For example, if another Web module contains a reference to the Web module that this factory creates, you may not want to allow the WebSnap application to free the Web module that this factory creates while the other module exists. 

In TAbstractWebModuleFactory, PreventDestruction is abstract or, in C++ terminology, pure virtual, meaning it has no implementation. Descendant classes must override this method to provide an implementation that prevents the Web module from being freed. 

CacheMode