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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def listener_create_event(self, listener_info):
 """Process listener create event. This is lbaas v2 vif will be plugged into ovs when first listener is created and unpluged from ovs when last listener is deleted """

        listener_data = listener_info.get('listener')
        lb_list = listener_data.get('loadbalancers')
        for lb in lb_list:
            lb_id = lb.get('id')
            req = dict(instance_id=(lb_id.replace('-', '')))
            instances = self.get_vms_for_this_req(**req)
            if not instances:
                lb_info = self.neutronclient.show_loadbalancer(lb_id)
                if lb_info:
                    port_id = lb_info["loadbalancer"]["vip_port_id"]
                    self.add_lbaas_port(port_id, lb_id)
            else:
                LOG.info("lbaas port for lb %s already added" % lb_id)