$container->get('fos_user.user_manager'); NOT WORKING FOR ME
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I am trying to do some of the simplest things with fosUserBundle but I can't even access the         

    $container->get('fos_user.user_manager'); 
it's supposed to be a service... I get:

    Fatal error: Call to a member function get() on a non-object

If I try 

    $userManager = $this->$container->get('fos_user.user_manager');

I get

    Fatal error: Cannot access empty property in...

Any clue what I am doing wrong?
Do I have to EXTEND a certain class of USE a certain thing in order for this get('fos_user.user_manager') to work or what?