问为什么JMockit的@Injectable不适用于所有相关字段？

EN

@Service
@Scope("prototype")
public class A {
    @Autowired IC c;
    public IC getC() { return c; }

    // do something using C in the method body
    public void doSomething() {}
}

@Service
@Scope("prototype")
public class B {
    @Autowired IC c;
    public IC getC() { return c; }

    // do something using C in the method body
    public void doSomething() {}
}

public interface IC { void doSomething(); }

@Service
@Scope("prototype")
public class C implements IC {
    @Override
    public void doSomething() {}
}

@Service
public class D {
    @Autowired IC c;
    @Autowired B b;
    @Autowired A a;

    public IC getC() { return c; }
    public B getB() { return b; }
    public A getA() { return a; }
}

public class TestClass {
    @Tested(fullyInitialized = true) D d;
    @Injectable IC c;
    @Tested @Injectable A a;
    @Tested @Injectable B b;

    @Test
    public void test() {
        // expectations are recorded here
        assertNotNull(d.getC());
        assertNotNull(d.getB().getC());
        // Null reference 
        assertNotNull(d.getA().getC());
    }
}