code: @Koan
      public void makeTheProductOfIAndJ(){
          int i = 10;
          int j = 5;
          int product = 0;
  
          /* (@_@) */
          product = i * j;
          /* (^_^) */
  
          assertThat(product, is(50));
      }
docs: In this exercise students will learn how to use the multiplication operator in Java