Javadoc
A special IPreparedCheckpointer that does nothing, which can be used when preparing a checkpoint at the current
checkpoint sequence number where it is never necessary to do another checkpoint.
This simplifies programming by preventing application developers from having to reason about whether
their application has processed records before calling prepareCheckpoint
Here's why it's safe to do nothing:
The only way to checkpoint at current checkpoint value is to have a record processor that gets
initialized, processes 0 records, then calls prepareCheckpoint(). The value in the table is the same, so there's
no reason to overwrite it with another copy of itself.