I want to extract some text from an HTML element in Selenium and Javascript.

```
<span class="myAttribute"> 
  <b>SomeValueToIgnore</b> 
  <span class="ignoreWhatsInside">
    <em>ignore_that</em>
  </span>
  GiveMeJustThat_NothingElse
</span>

```

How can I extract the text 'GiveMeJustThat\_NothingElse' from the span element in Javascript / Selenium?
Unfortunately I cannot put the text 'GiveMe...' into an own tag, because that would break other tests.