docs: def remoteIndexer2to3(oldIndexer):
      """
      The documentType keyword was added to all indexable items.  Indexes need to
      be regenerated for this to take effect.  Also, PyLucene no longer stores
      the text of messages it indexes, so deleting and re-creating the indexes
      will make them much smaller.
      """
      newIndexer = oldIndexer.upgradeVersion(
          oldIndexer.typeName, 2, 3,
          indexCount=oldIndexer.indexCount,
          installedOn=oldIndexer.installedOn,
          indexDirectory=oldIndexer.indexDirectory)
      # the 3->4 upgrader for PyLuceneIndexer calls reset(), so don't do it
      # here.  also, it won't work because it's a DummyItem
      if oldIndexer.typeName != PyLuceneIndexer.typeName:
          newIndexer.reset()
      return newIndexer