blacck applied

tests/lib/test_ts_operators.py

@@ -5,4 +5,6 @@ import pandas as pd
 
 
 def test_butterFilter():
-    assert (butterFilter(pd.Series([1, -1]*100), cutoff=0.1) - pd.Series([1, -1]*100)).mean() < 0.5
+    assert (
+        butterFilter(pd.Series([1, -1] * 100), cutoff=0.1) - pd.Series([1, -1] * 100)
+    ).mean() < 0.5