diff --git a/healpix_alchemy/func.py b/healpix_alchemy/func.py
index 35b2e9f..edd2434 100644
--- a/healpix_alchemy/func.py
+++ b/healpix_alchemy/func.py
@@ -4,5 +4,6 @@
 from .types import Tile as _Tile
 
 
+
 def union(tiles):
     return _func.unnest(_func.range_agg(tiles), type_=_Tile)