IntelliJ IDEA提取委托重构

public class Foo {
    private String b;
    public String getInfo() {
        return ("(" + b + ")");
    }
    ...
}
public class Bar {
    Foo foo;
    String t2 = foo.getInfo();
    ...
}

public class Foo {
    private final Info info = new Info();
    public String getInfo() {
        return info.getInfo();
    }
    ...
}
public class Info {
    private String b;
    public Info() {}
    public String getInfo() {
        return ("(" + b + ")");
    }
}
public class Bar {
    Foo foo;
    String t2 = foo.getInfo();
    ...
}