code: def pyLuceneIndexer4to5(old):
      
      new = old.upgradeVersion(PyLuceneIndexer.typeName, 4, 5,
                               indexCount=old.indexCount,
                               installedOn=old.installedOn,
                               indexDirectory=old.indexDirectory)
      new.reset()
      new.store.powerUp(new, ixmantissa.IFulltextIndexer)
      return new
docs: Copy attributes, reset index due because information about deleted
      documents has been lost, and power up for IFulltextIndexer so other code
      can find this item.