<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def cfg_lldp_interface(self, protocol_interface, phy_interface=None):
 """Cfg LLDP on interface and create object. """

        if phy_interface is None:
            phy_interface = protocol_interface
        self.create_attr_obj(protocol_interface, phy_interface)
        ret = self.pub_lldp.enable_lldp(protocol_interface)
        attr_obj = self.get_attr_obj(protocol_interface)
        attr_obj.update_lldp_status(ret)