@Override
    @SuppressWarnings("nls")
    protected void initialize(Class<?> type, Object oldInstance,
            Object newInstance, Encoder enc) {
        // Call the initialization of the super type
        super.initialize(type, oldInstance, newInstance, enc);
        // Continue only if initializing the "current" type
        if (type != oldInstance.getClass()) {
            return;
        }
        
        
        JFrame frame = (JFrame) oldInstance;
        Container container = frame.getContentPane();
    	int count = container.getComponentCount();
    	if(count != 0) {
    		Expression getterExp = new Expression(frame,
					"getContentPane", null);
    		try {
                // Calculate the old value of the property
                Object oldVal = getterExp.getValue();
                // Write the getter expression to the encoder
                enc.writeExpression(getterExp);
                // Get the target value that exists in the new environment
                Object targetVal = enc.get(oldVal);
                // Get the current property value in the new environment
                Object newVal = null;
				JFrame newFrame = (JFrame) newInstance;
				newVal = new Expression(newFrame.getContentPane(), newFrame,
						"getContentPane", null).getValue();
                /*
				 * Make the target value and current property value equivalent
				 * in the new environment
				 */
                if (null == targetVal) {
                    if (null != newVal) {
                        // Set to null
                        Statement setterStm = new Statement(oldInstance, "setContentPane",
								new Object[] { null });
                        enc.writeStatement(setterStm);
                    }
                } else {
                    PersistenceDelegate pd = enc
                            .getPersistenceDelegate(targetVal.getClass());
                    if (!pd.mutatesTo(targetVal, newVal)) {
                        Statement setterStm = new Statement(oldInstance, "setContentPane",
                                new Object[] { oldVal });
                        enc.writeStatement(setterStm);
                    }
                }
            } catch (Exception ex) {
                enc.getExceptionListener().exceptionThrown(ex);
            }
    	}
	}