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The type of the parameter passed to AuthenticatedWebApplication#onUnauthorizedPage() has changed from org.apache.wicket.Page to org.apache.wicket.Component because this is an instance of a page that is partially constructed. Only the constructor of org.apache.wicket.Component is fully executed. All super constructors are not executed and the instance is not really a Page.
PropertyColumn#createLabelModel has been renamed to getDataModel
The property column from wicket-extensions has some methods renamed to better reflect their meaning.
Behavior changes
org.apache.wicket.request.Url#getQueryString WICKET-4664
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