$env_key may undefined value. I should check $env_key before use it.
Checking in changes prior to tagging of version 0.36.

Changelog diff is:

diff --git Changes Changes
index 533a46f..731f499 100644
--- Changes
+++ Changes
@@ -2,6 +2,10 @@ Revision history for Perl extension Test-Kantan

 {{$NEXT}}

+0.36 2014-08-26T21:08:55Z
+
+    - suppress UUV
+
 0.35 2014-08-26T20:53:11Z

     - First CPAN release