Unit test TestSettings in project addon/yui fails

first due to javax/servlet/http/HttpSession missing, but if added the stack trace the following is generated:

Tests run: 5, Failures: 0, Errors: 2, Skipped: 0, Time elapsed: 1.03 sec <<< FAILURE!
testWireFrameSettings(org.hippoecm.frontend.plugins.yui.javascript.TestSettings) Time elapsed: 0.726 sec <<< ERROR!
org.apache.wicket.markup.MarkupNotFoundException: Markup of type 'html' for component 'org.hippoecm.frontend.plugins.yui.javascript.TestSettings$TestPage' not found. Enable debug messages for org.apache.wicket.util.resource to get a list of all filenames tried:
[Page class = org.hippoecm.frontend.plugins.yui.javascript.TestSettings$TestPage, id = 0, version = 0]
at org.apache.wicket.MarkupContainer.getAssociatedMarkupStream(MarkupContainer.java:355)
at org.apache.wicket.Page.onRender(Page.java:1463)
at org.apache.wicket.Component.render(Component.java:2324)
at org.apache.wicket.Page.renderPage(Page.java:904)
at org.apache.wicket.request.target.component.BookmarkablePageRequestTarget.respond(BookmarkablePageRequestTarget.java:231)
at org.apache.wicket.request.AbstractRequestCycleProcessor.respond(AbstractRequestCycleProcessor.java:104)
at org.apache.wicket.RequestCycle.processEventsAndRespond(RequestCycle.java:1181)
at org.apache.wicket.RequestCycle.step(RequestCycle.java:1252)
at org.apache.wicket.RequestCycle.steps(RequestCycle.java:1353)
at org.apache.wicket.RequestCycle.request(RequestCycle.java:539)
at org.apache.wicket.protocol.http.MockWebApplication.processRequestCycle(MockWebApplication.java:458)
at org.apache.wicket.protocol.http.MockWebApplication.processRequestCycle(MockWebApplication.java:367)
at org.apache.wicket.util.tester.BaseWicketTester.startPage(BaseWicketTester.java:289)
at org.hippoecm.frontend.plugins.yui.javascript.TestSettings.testWireFrameSettings(TestSettings.java:143)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at junit.framework.TestCase.runTest(TestCase.java:168)
at junit.framework.TestCase.runBare(TestCase.java:134)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:81)
at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:62)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:140)
at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:165)
at org.apache.maven.surefire.Surefire.run(Surefire.java:107)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:289)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:993)
Caused by: org.apache.wicket.markup.MarkupNotFoundException: Markup not found. Component class: org.hippoecm.frontend.plugins.yui.javascript.TestSettings$TestPage Enable debug messages for org.apache.wicket.util.resource to get a list of all filenames tried