设计一款interface A，要求其中至少包含4个方法，分别是login、logout、getUserInfo和updateUserInfo。请以markdown的形式返回设计代码。
user
```markdown
## Interface A Design

### Interface Description
Interface A is designed to provide essential user management functionalities. It includes methods to handle user authentication and information retrieval and modification.

### Methods

- **login**: This method is used to authenticate a user.
- **logout**: This method is used to log out a user from the system.
- **getUserInfo**: This method retrieves the information of the logged-in user.
- **updateUserInfo**: This method allows the user to update their information.

### Interface Definition

```java
public interface A {
    // Logs in the user with the provided credentials
    boolean login(String username, String password);
    
    // Logs out the current user
    void logout();
    
    // Retrieves the information of the current user
    User getUserInfo();
    
    // Updates the user's information
    boolean updateUserInfo(User updatedInfo);
}
```
```

Note: The `User` class should be defined separately to represent user information.
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