Not able to identify last item in list slightly

Hi 

I have the Sling model in that i have list like below 

public List<customList> getCustomProducts() {
    return customProducts;
}

When i tried to identify the last item of list like below

<sly data-sly-list.product="${productModel.customProducts}">
    <a href="${product.link}"><strong> ${product.name}</strong> </a>

    <sly data-sly-test="${!product.last}">
       <span class="separator">|</span>
    </sly>

</sly>

in above code  <span class="separator">|</span> is printing for last item as well

if list contains 3 items the | should print 2 times like below

product1 | product2 | product 3 

But its printing like 

product1 | product2 | product 3 |

can some help me how to identify the last item from list so that or how i can achieve this