which directory to save extends OAuth2 files?

Yii 2.0 General Discussions
1

hello guys, i am new for yii2.

and i am reading http://www.yiiframework.com/doc-2.0/ext-authclient-index.html

have some question to asking:

in the "Creating your own auth clients" section some code




use yii\authclient\OAuth2;


class MyAuthClient extends OAuth2

{

}

which directory should i save extends OAuth2 files?