After a moveChunk, this workload checks that mongos sees the same number of documents in the moved range, but the error message it uses says "number of chunks in partition seen by mongos changed" when it should say "number of documents in range seen by mongos changed" instead. It should also include the bounds of the range to simplify debugging.

https://github.com/mongodb/mongo/blob/eda72588a7/jstests/concurrency/fsm_workloads/sharded_moveChunk_partitioned.js#L142-L145