I have
$user = $this->Auth->user();
which retrieves the current user from the session.
I want to make an admin user be able to 'act as' a customer. And I was hoping to be able to just replace the customer_id in the user session when they enter the customer interface.
$user['User']['customer_id'] = 4;
This doesn't work because I can't find a way to push the $user data back into Auth