if (left == null || left instanceof JThisExpression) {
if (left instanceof JThisExpression) {
                    public Object visitFieldExpression(JFieldAccessExpression self,                            JExpression left, String fieldIdent) {                        JFieldAccessExpression f1 =                             (JFieldAccessExpression)super.visitFieldExpression(self,left,fieldIdent);                        if (left == null || left instanceof JThisExpression) {                            f1.setPrefix(new JTypeNameExpression(                                    left.getTokenReference(),                                    s.getIdent()));                        }                        return f1;                    }