human
Solve the following python programming problem given the following code:
def discover_auth_systems() : 
    "Discover the available auth-systems.

    This won't take into account the old style auth-systems.
    " 
    global _discovered_plugins 
    _discovered_plugins = { 
        
} 
    def add_plugin(ext) : 
        _discovered_plugins [ext.name] = ext.plugin 
ep_namespace = 'rackclient.openstack.common.apiclient.auth' 
    mgr = extension.ExtensionManager (ep_namespace) 
    mgr.map (mgr) 

    
    

    Fix the buggy line: mgr.map (mgr)
assistant
#Here is Python program to fix the buggy line: mgr.

mgr.map (def add_plugin()