cakephp 3的插件是i18n无法正常工作

plugin of cakephp 3 is i18n not working.

I created po file. plugin is Themes

Root\plugins\Example\src\Locale\ja_JP\example.po

http://book.cakephp.org/3.0/en/core-libraries/internationalization-and-localization.html

I am not good at English. Regards.

Add code 01/03/2016

src\Controller\UsersController.php
public function beforeRender(Event $event)
{
    $this->viewBuilder()->theme('Example');
}

plugins\Example\src\Template\Users\login.ctp
<?= $this->Form->button(__('Login')); ?>

plugins\Example\src\Locale\ja_JP\default.pot
#: Template/Users/login.ctp:8
msgid "Login"
msgstr "logged in"

But the display does not change. Error does not occur.

Try inserting this

use Cake\I18n\Time;