This method is called on a StatefulDictionary when it belongs to a static Toolbar item and the Init event fires on the UltraWebToolbar. It signifies that all values assigned prior to this point came from the web form itself, and do not need to be persisted in viewstate (thereby keeping the size of viewstate to a minimum).
An implementation may ignore a flush request made after it has already turned on tracking of the view state by calling Track.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2