diff --git a/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DataAvailability.java b/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DataAvailability.java
index 3d7c963..8342278 100644
--- a/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DataAvailability.java
+++ b/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DataAvailability.java
@@ -1,3 +1,4 @@
+// License: GPL. For details, see LICENSE file.
 package org.openstreetmap.josm.plugins.mapwithai.backend;
 
 import java.io.IOException;
diff --git a/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DownloadMapWithAITask.java b/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DownloadMapWithAITask.java
index 649f2a8..2f7c8f8 100644
--- a/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DownloadMapWithAITask.java
+++ b/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/DownloadMapWithAITask.java
@@ -1,3 +1,4 @@
+// License: GPL. For details, see LICENSE file.
 package org.openstreetmap.josm.plugins.mapwithai.backend;
 
 import static org.openstreetmap.josm.tools.I18n.tr;
diff --git a/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnable.java b/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnable.java
index de5c5fb..f5fc651 100644
--- a/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnable.java
+++ b/src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnable.java
@@ -59,7 +59,6 @@ public class GetDataRunnable extends RecursiveTask<DataSet> {
 
     private static final int MAX_NUMBER_OF_BBOXES_TO_PROCESS = 1;
     private static final String SERVER_ID_KEY = "server_id";
-    private static final int DEFAULT_TIMEOUT = 50_000; // 50 seconds
 
     private static final double ARTIFACT_ANGLE = 0.1745; // 10 degrees in radians
 
diff --git a/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnableTest.java b/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnableTest.java
index 0afd492..e707ab5 100644
--- a/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnableTest.java
+++ b/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/GetDataRunnableTest.java
@@ -3,6 +3,7 @@ package org.openstreetmap.josm.plugins.mapwithai.backend;
 
 import static com.github.tomakehurst.wiremock.core.WireMockConfiguration.options;
 import static org.junit.Assume.assumeTrue;
+import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
@@ -27,6 +28,8 @@ import org.openstreetmap.josm.data.osm.Node;
 import org.openstreetmap.josm.data.osm.Way;
 import org.openstreetmap.josm.data.osm.WaySegment;
 import org.openstreetmap.josm.data.projection.ProjectionRegistry;
+import org.openstreetmap.josm.gui.MainApplication;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
 import org.openstreetmap.josm.testutils.JOSMTestRules;
 import org.openstreetmap.josm.tools.Geometry;
 
@@ -42,7 +45,7 @@ public class GetDataRunnableTest {
     public void setUp() {
         wireMock.start();
         MapWithAIPreferenceHelper.setMapWithAIURLs(MapWithAIPreferenceHelper.getMapWithAIURLs().stream().map(map -> {
-            map.put("url", getDefaultMapWithAIAPIForTest(
+            map.put("url", getDefaultMapWithAIAPIForTest(wireMock,
                     map.getOrDefault("url", MapWithAIPreferenceHelper.DEFAULT_MAPWITHAI_API)));
             return map;
         }).collect(Collectors.toList()));
@@ -53,11 +56,11 @@ public class GetDataRunnableTest {
         wireMock.stop();
     }
 
-    private String getDefaultMapWithAIAPIForTest(String url) {
-        return getDefaultMapWithAIAPIForTest(url, "https://www.facebook.com");
+    public static String getDefaultMapWithAIAPIForTest(WireMockServer wireMock, String url) {
+        return getDefaultMapWithAIAPIForTest(wireMock, url, "https://www.facebook.com");
     }
 
-    private String getDefaultMapWithAIAPIForTest(String url, String wireMockReplace) {
+    public static String getDefaultMapWithAIAPIForTest(WireMockServer wireMock, String url, String wireMockReplace) {
         return url.replace(wireMockReplace, wireMock.baseUrl());
     }
 
@@ -121,4 +124,29 @@ public class GetDataRunnableTest {
         assertFalse(ds.isEmpty());
         assertFalse(ds.allNonDeletedPrimitives().isEmpty());
     }
+
+    @Test
+    public void testAlreadyAddedElements() {
+        Way addedWay = TestUtils.newWay("", new Node(new LatLon(0, 0)), new Node(new LatLon(1, 1)));
+        Way duplicateWay = TestUtils.newWay("", new Node(new LatLon(0, 0)), new Node(new LatLon(1, 1)));
+        Way nonDuplicateWay = TestUtils.newWay("", new Node(new LatLon(0, 0)), new Node(new LatLon(1, 2)));
+
+        DataSet osm = new DataSet();
+        addedWay.getNodes().forEach(osm::addPrimitive);
+        osm.addPrimitive(addedWay);
+
+        DataSet conflationDs = new DataSet();
+        for (Way way : Arrays.asList(duplicateWay, nonDuplicateWay)) {
+            way.getNodes().forEach(conflationDs::addPrimitive);
+            conflationDs.addPrimitive(way);
+        }
+
+        MainApplication.getLayerManager().addLayer(new OsmDataLayer(osm, "OSM Layer", null));
+        GetDataRunnable.removeAlreadyAddedData(conflationDs);
+
+        assertAll(() -> assertTrue(duplicateWay.isDeleted(), "The duplicate way should be deleted"),
+                () -> duplicateWay.getNodes()
+                        .forEach(node -> assertTrue(node.isDeleted(), "The duplicate way nodes should be deleted")),
+                () -> assertFalse(nonDuplicateWay.isDeleted(), "The non-duplicate way should not be deleted"));
+    }
 }
diff --git a/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/MapWithAIDataUtilsTest.java b/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/MapWithAIDataUtilsTest.java
index 8291e20..e9d73c5 100644
--- a/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/MapWithAIDataUtilsTest.java
+++ b/test/unit/org/openstreetmap/josm/plugins/mapwithai/backend/MapWithAIDataUtilsTest.java
@@ -22,6 +22,7 @@ import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.data.Bounds;
 import org.openstreetmap.josm.data.coor.LatLon;
 import org.openstreetmap.josm.data.gpx.GpxData;
 import org.openstreetmap.josm.data.gpx.WayPoint;
@@ -117,10 +118,13 @@ public class MapWithAIDataUtilsTest {
     }
 
     public static BBox getTestBBox() {
-        final BBox testBBox = new BBox();
-        testBBox.add(new LatLon(39.0734162, -108.5707107));
-        testBBox.add(new LatLon(39.0738791, -108.5715723));
-        return testBBox;
+        return getTestBounds().toBBox();
+    }
+
+    public static Bounds getTestBounds() {
+        Bounds bound = new Bounds(39.0734162, -108.5707107);
+        bound.extend(39.0738791, -108.5715723);
+        return bound;
     }
 
     @Test