Similar to my comments on `parallelize()`, I'd change this to actually run an action on the coalesced RDD that shows the reduction in partitions.  You might also want to increase the number of partitions in parallelize (using, say, 5 partitions) before calling coalesce.

Also, try to avoid showing implementation-specific details like `CoalescedRDD[11] at coalesce at NativeMethodAccessorImpl.java:-2` in user-facing docs.