You have a package tools with classes:

You have a package tools with classes:

class Helper {
    void assist() {
        System.out.println("Helping...");
    }
}

public class Tool {
    public static void main(String[] args) {
        Helper h = new Helper();
        h.assist();
    }
}

You want to allow only classes inside tools to use Helper and its assist() method, but prevent access from outside. Which is the best way to achieve this?