diff -r d42b6cf00fa6 -r c507c363625e tests/tools/check_source.sh
--- a/tests/tools/check_source.sh	Fri Sep 29 15:36:33 2017 +0300
+++ b/tests/tools/check_source.sh	Fri Sep 29 16:26:15 2017 +0300
@@ -210,7 +210,8 @@
     enable=$enable,C0412          # (ungrouped-imports) Imports from package X are not grouped
     enable=$enable,C0321          # (multiple-statements) More than one statement on a single line
     enable=$enable,W0231          # (super-init-not-called) __init__ method from base class is not called
-    
+    enable=$enable,W0105          # (pointless-string-statement) String statement has no effect    
+
     # enable=$enable,W0403        # relative import
     # enable=$enable,W0622        # (redefined-builtin) Redefining built-in
     # enable=$enable,W0612        # unused-variable