--- a/configmix/config.py	Sun Apr 25 12:54:02 2021 +0200
+++ b/configmix/config.py	Sun Apr 25 14:05:16 2021 +0200
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # :-
-# :Copyright: (c) 2015-2020, Franz Glasner. All rights reserved.
+# :Copyright: (c) 2015-2021, Franz Glasner. All rights reserved.
 # :License:   BSD-3-Clause. See LICENSE.txt for details.
 # :-
 """The unified configuration dictionary with attribute support or
@@ -202,7 +202,7 @@
     _ENDTOK = u(b"}}")
 
     def expand_variable(self, s):
-        """Expand variables in a single string"""
+        """Expand variables in the single string `s`"""
         start = s.find(self._STARTTOK, 0)
         while start != -1:
             end = s.find(self._ENDTOK, start)