[pre-commit.ci] auto fixes from pre-commit.com hooks

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Author: pre-commit-ci[bot]

docs/source/images/visualize_grids.py

@@ -4,6 +4,7 @@
 This example is based on the matplotlib demo of a PathPatch object,
 https://matplotlib.org/examples/shapes_and_collections/path_patch_demo.html.
 """
+
 import matplotlib.patches as mpatches
 import matplotlib.path as mpath
 import matplotlib.pyplot as plt