-e 's,@FIRST_KEY\@,key = self.db.firstkey(),g' \
-e 's,@CHECK_KEY\@,while key is not None:,g' \
-e 's,@NEXT_KEY\@,key = self.db.nextkey(key),g' \
-e 's,@FIRST_KEY\@,key = self.db.firstkey(),g' \
-e 's,@CHECK_KEY\@,while key is not None:,g' \
-e 's,@NEXT_KEY\@,key = self.db.nextkey(key),g' \