| SAXONICA | 
saxon:string-to-hexBinary($in as xs:string, $encoding as xs:string) ==> xs:hexBinary
This function takes as input a string and the name of a character
            encoding (for example "UTF8"). It encodes the contents of the string value as a sequence of bytes
            using a particular encoding, and returns the xs:hexBinary representation
            of this sequence of bytes.