private static boolean isPosition(XPathExpression expression) {
            expression = ExpectedTypeUtil.unparenthesize(expression);

            if (!(expression instanceof XPathFunctionCall call)) {
                return false;
            }

          final PrefixedName qName = call.getQName();
            if (qName.getPrefix() != null) return false;
            return "position".equals(qName.getLocalName());
        }
private static boolean isPosition(XPathExpression expression)