Index: trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/Condition.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/Condition.java	(revision 10606)
+++ trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/Condition.java	(revision 10607)
@@ -30,4 +30,5 @@
 import org.openstreetmap.josm.tools.Utils;
 
+@FunctionalInterface
 public interface Condition {