@Test
    public void testLazyDocWithBigList() {
        DBCollection c = _db.getCollection("testLazyDotKeysPass");
        c.drop();

        DBObject obj = new BasicDBObject();
        ArrayList<Integer> arr = new ArrayList<Integer>();
        for(int i = 0; i < 20000; i++){
            arr.add(i);
        }
        
        obj.put("largeArray", arr);
        obj.put("randomstr", "asdfasdfa");
        
        long start = System.currentTimeMillis();
        c.insert(obj);
        System.out.println("Save obj: " + (System.currentTimeMillis() - start));
        
        //convert to a lazydbobject
        DefaultDBEncoder encoder = new DefaultDBEncoder();
        byte[] encodedBytes = encoder.encode(obj);

        LazyDBDecoder lazyDecoder = new LazyDBDecoder();
        DBObject lazyObj = lazyDecoder.decode(encodedBytes, c);

        start = System.currentTimeMillis();
        c.insert(lazyObj);
        System.out.println("Save lazy obj: " + (System.currentTimeMillis() - start));
        
        //convert lazy to a regular dbobject and save
        start = System.currentTimeMillis();
        LazyDBEncoder lazyEncoder = new LazyDBEncoder();
        BasicOutputBuffer outputBuffer = new BasicOutputBuffer();
        lazyEncoder.writeObject(outputBuffer, lazyObj);
        
        DefaultDBDecoder defDecode = new DefaultDBDecoder();
        DBObject normalObject = defDecode.decode(outputBuffer.toByteArray(), c);
        
        c.insert(normalObject);
        System.out.println("Lazy to Basic and save " + (System.currentTimeMillis() - start));
    }

Save obj: 72
Save lazy obj: 35194
Lazy to Basic and save 131