Unit test case covering creating an empty URL using Url::factory()

I really like the Guzzle Url class. However (to me) it has a small flaw: 

    $url = Url::factory("");
    echo $url;
    
    // My expected result: ""
    // The actual result: "/"

Is this expected behaviour? 
To me, I would expect the result to be an empty string (""), i.e. same as I passed. 

P.S.
I know this pull request doesn't solve it. Whenever I get time, I'll look into the code more and see if I can find how to fix it. I just wanted to share my findings and maybe someone else finds the solution faster?