Methods in interface are public implicitly
WICKET-5471 Store the page if it is known that it will be used in a following request

(cherry picked from commit 23172242b84704d8c95bbe168198c99d8b0f5ec4)
WICKET-5472 PackageResource#internalGetResourceStream() should return ProcessingResourceStream only when the resource is existing

(cherry picked from commit 1cc56f56aedbb9f0da0c6e1df35a441106568e72)