I use an XContentBuilder object to build a Json string.

```
XContentBuilder builder = XContentFactory.jsonBuilder().startObject()
                .field(Constants.OSM_ID, doc.getOsmId())
                .field(Constants.OSM_TYPE, doc.getOsmType())
                .field(Constants.OSM_KEY, doc.getTagKey())
                .field(Constants.OSM_VALUE, doc.getTagValue())
                .field(Constants.IMPORTANCE, doc.getImportance());

```

Now I would like to System.out the resulting Json String. How can I do this?