human
Solve the following python programming problem given the following code:
def start(self) : 
    super (OVSNeutronAgentRyuApp, self).start () 
    def _make_br_cls(br_cls) : 
        return functools.partial (br_cls, ryu_app = self) 
bridge_classes = { 
        'br_int' : _make_br_cls (br_int.OVSIntegrationBridge), 
        'br_phys' : _make_br_cls (br_phys.OVSPhysicalBridge), 
        'br_tun' : _make_br_cls (br_tun.OVSTunnelBridge), 
} 
    return hub.spawn (agent_main_wrapper, _make_br_cls) 

    
    

    Fix the buggy line: return hub.spawn (agent_main_wrapper, _make_br_cls)
assistant
#Here is Python code to fix the buggy line: return hub.

return hub.spawn (agent_main_wrapper, bridge_classes)