Index: src/org/openstreetmap/josm/gui/mappaint/mapcss/ExpressionFactory.java
===================================================================
--- src/org/openstreetmap/josm/gui/mappaint/mapcss/ExpressionFactory.java	(revision 15196)
+++ src/org/openstreetmap/josm/gui/mappaint/mapcss/ExpressionFactory.java	(working copy)
@@ -572,13 +572,13 @@
         }
 
         /**
-         * Returns true if role is in relation. Returns false if not a relation or it does not have the role.
+         * Returns the number of primitives in a relation with the specified roles.
          * @param env the environment
          * @param roles The roles to count in the relation
          * @return The number of relation members with the specified role
          * @since 15196
          */
-        public static int count_roles(final Environment env, String... roles) { // NO_UCD (unused code)
+        public static int count_roles(final Environment env, String roles) { // NO_UCD (unused code)
             int rValue = 0;
             if (env.osm instanceof Relation) {
                 List<String> roleList = Arrays.asList(roles);