在实例化Guice模块时，如何使类的构造函数单元可测试？

// 待测试的类
public class MyClass {
  private MyDependency dependency;

  @Inject
  public MyClass(MyDependency dependency) {
    this.dependency = dependency;
  }

  public int add(int a, int b) {
    return dependency.add(a, b);
  }
}

// 依赖接口
public interface MyDependency {
  int add(int a, int b);
}

// 依赖实现类
public class MyDependencyImpl implements MyDependency {
  public int add(int a, int b) {
    return a + b;
  }
}

// 测试类
public class MyClassTest {
  private MyClass myClass;

  @Before
  public void setup() {
    MyDependency mockDependency = Mockito.mock(MyDependency.class);
    Mockito.when(mockDependency.add(2, 3)).thenReturn(5);

    Injector injector = Guice.createInjector(new AbstractModule() {
      protected void configure() {
        bind(MyDependency.class).toInstance(mockDependency);
      }
    });

    myClass = injector.getInstance(MyClass.class);
  }

  @Test
  public void testAdd() {
    int result = myClass.add(2, 3);
    assertEquals(5, result);
  }
}