```
public class A{
  private B b;
}

public class B{
}

```

applicationContext.xml

```
<bean id="aBean" class="A">
<property name="b">  ???  </property>
</bean>

```

How to create an instance of A with b = null when using `context.getBean("aBean")`?

I have tried `<property name="b"><null/></property>`, but this doesn't work.