How many documents in each Lucene segment?

[Shawn Heisey]

Is there any way to easily determine how many documents exist in a 
Lucene index segment?  Ideally I want to check the document counts in 
segments on an index that is being built by a large MySQL dataimport, 
before the dataimport completes.  If that's not possible, I can take 
steps to do a smaller import and make sure the changes are committed.

Thanks,
Shawn