I am pretty new to programming so be patient with my question please 
I need to evaluate the content of a selector but I have no idea how since it is not a simple string but either a green tick or a red cross. The HTML for the green tick is:
<a class="fa fa-check" style="color: green"></a>
and the selector is:
body > main > div > div.grid > table > tbody > tr:nth-child(1) > td:nth-child(7) > a
How do I evaluate that content since an assertion with withText will fail. I know you can use an assertion with withAttribute but I have no idea how to bring the two together.
I know I can use something like this but what is the attribute in the above HTML?
.expect(selector.withAttribute(attrName [, attrValue]).exists).ok()