public Json removePadding(String padding) {
        String text = getFirstSourceText();
        XTokenQueue tokenQueue = new XTokenQueue(text);
        tokenQueue.consumeWhitespace();
        tokenQueue.consume(padding);
        tokenQueue.consumeWhitespace();
        String chompBalanced = tokenQueue.chompBalancedNotInQuotes('(', ')');
        return new Json(chompBalanced);
    }
remove padding for JSONP
@param padding padding
@return json after padding removed
webmagic-core/src/main/java/us/codecraft/webmagic/selector/Json.java