Index: trunk/test/unit/org/openstreetmap/josm/gui/preferences/imagery/ImageryPreferenceTestIT.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/preferences/imagery/ImageryPreferenceTestIT.java	(revision 14791)
+++ trunk/test/unit/org/openstreetmap/josm/gui/preferences/imagery/ImageryPreferenceTestIT.java	(revision 14792)
@@ -12,5 +12,4 @@
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
@@ -108,6 +107,6 @@
 
     private static TMSCachedTileLoaderJob helper;
-    private static List<String> errorsToIgnore;
-    private static List<String> notIgnoredErrors;
+    private static final List<String> errorsToIgnore = new ArrayList<>();
+    private static final List<String> notIgnoredErrors = new ArrayList<>();
 
     /**
@@ -118,6 +117,6 @@
     public static void beforeClass() throws IOException {
         helper = new TMSCachedTileLoaderJob(null, null, new CacheAccess<>(null), new TileJobOptions(0, 0, null, 0), null);
-        errorsToIgnore = TestUtils.getIgnoredErrorMessages(ImageryPreferenceTestIT.class);
-        notIgnoredErrors = new LinkedList<>(errorsToIgnore);
+        errorsToIgnore.addAll(TestUtils.getIgnoredErrorMessages(ImageryPreferenceTestIT.class));
+        notIgnoredErrors.addAll(errorsToIgnore);
     }