private static Model parseAs( Resource root, String encoding, String lexicalForm )
{
String enc = encoding == null ? guessFrom( lexicalForm ) : encoding;
if (enc.equals( "N3" )) return parseAsN3( lexicalForm );
if (enc.equals( "RDF/XML" )) return parseAsXML( lexicalForm );
throw new UnknownEncodingException( root, encoding );
}