diff --git a/carculator_truck/inventory.py b/carculator_truck/inventory.py
index 0f0fe25..5ccaa86 100644
--- a/carculator_truck/inventory.py
+++ b/carculator_truck/inventory.py
@@ -1,6 +1,7 @@
 """
 inventory.py contains Inventory which provides all methods to solve inventories.
 """
+
 import warnings
 
 import numpy as np