unit testing - How to test a print method in Java using Junit

I have written a method that is printing output to a console. How should I test it?

public class PrinterForConsole implements Printer{



   public void printResult(List items) {
        for (Item item: items){
            System.out.println("Name: " + item.getName());
            System.out.println("Number: " + item.getNumber());

            }
        }
}

currently, my test looks like this

public class TestPrinter{
    @Test
    public void printResultTest() throws Exception {
            (am figuring out what to put here)

        }
}

I have read the solution at this post (thanks @Codebender and @KDM for highlighting this) but don't quite understand it. How does the solution there test the print(List items) method? Hence, asking it afresh here.