newDoc.field("map", map);
map.put("Luca", new ODocument().field("name", "Luca"));
map.put("Marcus", new ODocument().field("name", "Marcus"));
map.put("Cesare", new ODocument().field("name", "Cesare"));
String json = newDoc.toJSON();
ODocument loadedDoc = new ODocument().fromJSON(json);
Assert.assertTrue(newDoc.hasSameContentOf(loadedDoc));
Assert.assertTrue(loadedDoc.containsField("map"));