* @param config The configuration. This is needed because the patterns that are
* generated need access to schema information.
*/
private void registerIdrefKey(Configuration config) {
PatternFinder idref = IdrefTest.getInstance();
//Expression eval = new Atomizer(new ContextItemExpression(), config);
StringFn sf = (StringFn)SystemFunction.makeSystemFunction(
"string", new Expression[]{new ContextItemExpression()});
StringLiteral regex = new StringLiteral("\\s+");