/** Returns DBObject representing object with given id */
 private DBObject getById(MongoDbServer entity, String id) throws Exception {
   MongoClient mongoClient = new MongoClient(entity.getAttribute(SoftwareProcess.HOSTNAME));
   try {
     DB db = mongoClient.getDB(TEST_DB);
     DBCollection testCollection = db.getCollection(TEST_COLLECTION);
     return testCollection.findOne(new BasicDBObject("_id", new ObjectId(id)));
   } finally {
     mongoClient.close();
   }
 }
 /** Inserts new object with { key: value } at given server, returns new document's id */
 private String insert(MongoDbServer entity, String key, Object value) throws Exception {
   MongoClient mongoClient = new MongoClient(entity.getAttribute(SoftwareProcess.HOSTNAME));
   try {
     DB db = mongoClient.getDB(TEST_DB);
     DBCollection testCollection = db.getCollection(TEST_COLLECTION);
     BasicDBObject doc = new BasicDBObject(key, value);
     testCollection.insert(doc);
     ObjectId id = (ObjectId) doc.get("_id");
     return id.toString();
   } finally {
     mongoClient.close();
   }
 }