--- a/truffle/com.oracle.truffle.object.basic/src/com/oracle/truffle/object/basic/DefaultStrategy.java	Wed Oct 07 20:27:40 2015 +0200
+++ b/truffle/com.oracle.truffle.object.basic/src/com/oracle/truffle/object/basic/DefaultStrategy.java	Wed Oct 07 19:15:14 2015 +0200
@@ -22,6 +22,8 @@
  */
 package com.oracle.truffle.object.basic;
 
+import java.util.Objects;
+
 import com.oracle.truffle.api.object.DynamicObject;
 import com.oracle.truffle.api.object.Layout;
 import com.oracle.truffle.api.object.Location;
@@ -32,15 +34,16 @@
 import com.oracle.truffle.object.LocationImpl;
 import com.oracle.truffle.object.ShapeImpl;
 import com.oracle.truffle.object.ShapeImpl.BaseAllocator;
-import java.util.Objects;
 
-class DefaultStrategy implements LayoutStrategy {
+class DefaultStrategy extends LayoutStrategy {
+    @Override
     public boolean updateShape(DynamicObject object) {
         assert object.getShape().isValid();
         return false;
     }
 
-    public Shape returnCached(Shape newShape) {
+    @Override
+    public Shape ensureValid(Shape newShape) {
         assert newShape.isValid();
         return newShape;
     }
@@ -52,39 +55,33 @@
         return true;
     }
 
+    @Override
     public Shape ensureSpace(Shape shape, Location location) {
         Objects.requireNonNull(location);
         assert assertLocationInRange(shape, location);
         return shape;
     }
 
+    @Override
     public boolean isAutoExtArray() {
         return false;
     }
 
-    public Property generalizeProperty(DynamicObject object, Property oldProperty, Object value) {
-        Shape oldShape = object.getShape();
-        Location oldLocation = oldProperty.getLocation();
-        Location newLocation = ((BasicAllocator) oldShape.allocator()).locationForValueUpcast(value, oldLocation);
-        Property newProperty = oldProperty.relocate(newLocation);
-        Shape newShape = oldShape.replaceProperty(oldProperty, newProperty);
-        newProperty.setSafe(object, value, oldShape, newShape);
-        return newProperty;
-    }
-
-    public Property generalizeProperty(DynamicObject object, Property oldProperty, Object value, Shape currentShape, Shape oldNewShape) {
+    @Override
+    public ShapeAndProperty generalizeProperty(Property oldProperty, Object value, Shape currentShape, Shape nextShape) {
         Location oldLocation = oldProperty.getLocation();
         Location newLocation = ((BasicAllocator) currentShape.allocator()).locationForValueUpcast(value, oldLocation);
         Property newProperty = oldProperty.relocate(newLocation);
-        Shape newShape = oldNewShape.replaceProperty(oldProperty, newProperty);
-        newProperty.setSafe(object, value, currentShape, newShape);
-        return newProperty;
+        Shape newShape = nextShape.replaceProperty(oldProperty, newProperty);
+        return new ShapeAndProperty(newShape, newProperty);
     }
 
+    @Override
     public BaseAllocator createAllocator(Shape shape) {
         return new DefaultAllocatorImpl((ShapeImpl) shape);
     }
 
+    @Override
     public BaseAllocator createAllocator(Layout layout) {
         return new DefaultAllocatorImpl((LayoutImpl) layout);
     }