The following functions have a different signature:
* <code>fn:document-uri()</code> with 0 arguments
* <code>fn:string-join()</code> with 1 argument
* <code>fn:node-name()</code> with 0 arguments
* <code>fn:round()</code> with 2 arguments
* <code>fn:document-uri()</code> with 0 arguments
* <code>fn:node-name()</code> with 0 arguments
* <code>fn:data()</code> with 0 arguments