Incomplete List when retrieved data from secondary

To reproduce, you need a replicaset with at least two secondary nodes.

sbt "run mongodb://primary:27017,secondary0:27017,secondary1:27017/dbname"

The test will create a dbname.rmbug2 collection, empty it, and insert 2000 documents.

Then it will list the documents from mongodb to stdout with different ReadPreference: secondaryPreferred and primaryPreferred.

Expected: should print 2000 documents. Issue: only print 101 or 202 documents.

Output:

|total document inserted: 2000
|  total result from Secondary Preferred : 101
|  total result from Primary Preferred   : 2000