diff --git a/src/org/openstreetmap/josm/gui/mappaint/mapcss/Functions.java b/src/org/openstreetmap/josm/gui/mappaint/mapcss/Functions.java
index a14810572..dead2a43d 100644
--- a/src/org/openstreetmap/josm/gui/mappaint/mapcss/Functions.java
+++ b/src/org/openstreetmap/josm/gui/mappaint/mapcss/Functions.java
@@ -1175,4 +1175,21 @@ public final class Functions {
     public static boolean at(Environment env, double lat, double lon) { // NO_UCD (unused code)
         return new LatLon(lat, lon).equalsEpsilon(center(env));
     }
+
+    /**
+     * Test wheather each element of the list {@code lst} matches the regular expression {@code regexp}.
+     * @param regexp String
+     * @param lst list
+     * @return list of matches
+     * @since xxx
+     */
+    public static List<String> filter(String regexp, List<String> lst) { // NO_UCD (unused code)
+        List<String> dst = new ArrayList<String>();
+        for (String str : lst) {
+            if (str.matches(regexp)) {
+                dst.add(str);
+            }
+        }
+        return dst;
+    }
 }