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

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

backedarray/sparse_array.py

@@ -7,6 +7,7 @@
 .. _h5sparse: https://github.com/appier/h5sparse
 .. _Appier Inc.: https://www.appier.com/
 """
+
 from typing import NamedTuple, Tuple, Union
 
 import numpy as np