Code samples for a blog post - https://classcube.com/output-matching-runner/

PrintSquare.java

public class PrintSquare {

    public void printSquare() {
        // Your code goes here...
    }

}

PrintSquareRunner.java

public class PrintSquareRunner {

    public static void main(String... args) {

        PrintSquare ps = new PrintSquare();
        ps.printSquare();

    }

}