public function iAmLoggedAs($username, $password)
{
$this->visitPath('/login');
$page = $this->getSession()->getPage();
$page->fillField('store_user_form_type_login_email', $username);
$page->fillField('store_user_form_type_login_password', $password);
$page->pressButton('store_user_form_type_login_send');
}