diff --git a/tracetools_analysis/tracetools_analysis/analysis/utils.py b/tracetools_analysis/tracetools_analysis/analysis/utils.py
index 0085380..801116b 100644
--- a/tracetools_analysis/tracetools_analysis/analysis/utils.py
+++ b/tracetools_analysis/tracetools_analysis/analysis/utils.py
@@ -15,6 +15,7 @@
 """Module for data model utility class."""
 
 from typing import Mapping
+
 from pandas import DataFrame
 
 from .data_model import DataModel