diff -r 2753aad79678 -r e46fa477007b tests/subfiles.py
--- a/tests/subfiles.py	Fri May 24 14:20:18 2019 +0200
+++ b/tests/subfiles.py	Fri May 24 15:32:10 2019 +0300
@@ -6,7 +6,7 @@
 ini_path = Path(dirname(__file__)) / 'library-standards.ini'
 library_standards = ConfigParser()
 
-with open(ini_path) as file:
+with ini_path.open() as file:
     library_standards.read_file(file)
 
 def determinant_test(model):