Squashed commit of the following:

commit 43e5bba774e9e383dd55c665e82f6fcfc4ebfc4f
Author: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date:   Mon Apr 17 17:28:44 2017 +0900

    Add fix

commit 09610eebdf22ad048812bb86022504b2ad917e19
Author: Shinya Maeda <gitlab.shinyamaeda@gmail.com>
Date:   Mon Apr 17 17:03:49 2017 +0900

    Add trace test