JSoup Getting Text Without Wrapping Tag Under an Element

How do I get the following 'Some random text', and wrap it with a span?

e.g. I have the following element :

<div>
    Some random text
    <a href="some_url">Go to Link</a>
</div>

And I would have something like this :

<div>
    <span>Some random text</span>
    <a href="some_url">Go to Link</a>
</div>