Github user mars commented on the issue:
https://github.com/apache/incubator-predictionio/pull/441
@shimamoto Ah, this makes so much sense now ð² Not sure of a solution,
yet. I created a JIRA for this issue: [PIO-138 Batch predict fails when using a
PersistentModel](https://issues.apache.org/jira/browse/PIO-138). Let's continue
discussion for a fix there.---
