The word "selector" is standard in computer science nomenclature, especially within the web development field. See [what Wikipedia has to say about selector](https://en.wikipedia.org/wiki/Selector) to verify that the only legitimate use within web development cycles is the one intended and also [google selector](https://www.google.com/search?q=selector) to see that the first three results indeed confirm this usage. I prefer to avoid `$CssSelector`, as this is a generic XML selector and in reality constitutes an XPath selector, but using the name `XPathSelector` makes this somewhat obscure. I recommend that we maintain the name `$selector`.