Critical Description
MockWebApplication#setupRequestAndResponse always sets up a non ajax requestcycle.
this method is also used to setup the requestcycle for ajax related functionality (eg. BaseWicketTester#clickLink).
the consequence are:
a) the markup for expected ajax responses contains wicket tags and wicket attributes, although these are never rendered in ajax responses.
b) some unit tests (eg. AjaxTimerBehaviorTest#testAddToAjaxUpdate, ComponentBorderTest#testHideableBorder) succeed, when the same code in non-unit-test environment doesn't work, because there is no ajax request during testing, while there is one during normal execution.