@Override
    public String select(String text) {
        for (Selector selector : selectors) {
            if (text == null) {
                return null;
            }
            text = selector.select(text);
        }
        return text;
    }
All selectors will be arranged as a pipeline. <br>
The next selector uses the result of the previous as source.
@author code4crafter@gmail.com <br>
@since 0.2.0
webmagic-core/src/main/java/us/codecraft/webmagic/selector/AndSelector.java