Index: trunk/src/org/openstreetmap/josm/data/osm/AbstractPrimitive.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/AbstractPrimitive.java	(revision 13803)
+++ trunk/src/org/openstreetmap/josm/data/osm/AbstractPrimitive.java	(revision 13804)
@@ -650,24 +650,4 @@
 
     /**
-     * Returns true if the {@code key} corresponds to an OSM true value.
-     * @param key OSM key
-     * @return {@code true} if the {@code key} corresponds to an OSM true value
-     * @see OsmUtils#isTrue(String)
-     */
-    public final boolean isKeyTrue(String key) {
-        return OsmUtils.isTrue(get(key));
-    }
-
-    /**
-     * Returns true if the {@code key} corresponds to an OSM false value.
-     * @param key OSM key
-     * @return {@code true} if the {@code key} corresponds to an OSM false value
-     * @see OsmUtils#isFalse(String)
-     */
-    public final boolean isKeyFalse(String key) {
-        return OsmUtils.isFalse(get(key));
-    }
-
-    /**
      * Gets a key ignoring the case of the key
      * @param key The key to get
Index: trunk/src/org/openstreetmap/josm/data/osm/Tagged.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/Tagged.java	(revision 13803)
+++ trunk/src/org/openstreetmap/josm/data/osm/Tagged.java	(revision 13804)
@@ -199,3 +199,23 @@
      */
     void removeAll();
+
+    /**
+     * Returns true if the {@code key} corresponds to an OSM true value.
+     * @param key OSM key
+     * @return {@code true} if the {@code key} corresponds to an OSM true value
+     * @see OsmUtils#isTrue(String)
+     */
+    default boolean isKeyTrue(String key) {
+        return OsmUtils.isTrue(get(key));
+    }
+
+    /**
+     * Returns true if the {@code key} corresponds to an OSM false value.
+     * @param key OSM key
+     * @return {@code true} if the {@code key} corresponds to an OSM false value
+     * @see OsmUtils#isFalse(String)
+     */
+    default boolean isKeyFalse(String key) {
+        return OsmUtils.isFalse(get(key));
+    }
 }