Failing unit test in turnrestrictions plugin

[Don-vip]

I have updated unit tests of turnrestrictions plugin to replace JOSMFixture by new system and face a unit test failure I don't understand:

jenkins/job/JOSM-Plugins/lastCompletedBuild/jdk=JDK8/testReport/org.openstreetmap.josm.plugins.turnrestrictions.editor/JosmSelectionListModelTest/test_editLayerChanged/

junit.framework.AssertionFailedError: assert model.getSize() == 1
       |     |         |
       |     0         false
       org.openstreetmap.josm.plugins.turnrestrictions.editor.JosmSelectionListModel@6f6c2408
	at org.codehaus.groovy.runtime.InvokerHelper.assertFailed(InvokerHelper.java:402)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.assertFailed(ScriptBytecodeAdapter.java:650)
	at org.openstreetmap.josm.plugins.turnrestrictions.editor.JosmSelectionListModelTest.test_editLayerChanged(JosmSelectionListModelTest.groovy:148)
	at org.openstreetmap.josm.testutils.JOSMTestRules$1.evaluate(JOSMTestRules.java:143)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.lang.Thread.run(Thread.java:745)