kytos / mef_eline

        return flow_mod

    def _prepare_push_flow(self, *args):

        """Prepare push flow.

        Arguments:

            in_interface(str): Interface input.

            out_interface(str): Interface output.

            in_vlan(str): Vlan input.

            out_vlan(str): Vlan output.

        Return:

            dict: An python dictionary representing a FlowMod

        """

        # assign all arguments

        in_interface, out_interface, in_vlan, out_vlan = args

        flow_mod = self._prepare_flow_mod(in_interface, out_interface)

        # the service tag must be always pushed

        new_action = {"action_type": "set_vlan", "vlan_id": out_vlan}

        flow_mod["actions"].insert(0, new_action)

        new_action = {"action_type": "push_vlan", "tag_type": "s"}

        flow_mod["actions"].insert(0, new_action)

        if in_vlan:

            # if in_vlan is set, it must be included in the match

            flow_mod['match']['dl_vlan'] = in_vlan

            new_action = {"action_type": "pop_vlan"}

            flow_mod["actions"].insert(0, new_action)

        return flow_mod

    def _prepare_pop_flow(self, in_interface, out_interface, in_vlan,

                          out_vlan):

            flow_mod["actions"].insert(0, new_action)

        return flow_mod

    def _prepare_pop_flow(self, in_interface, out_interface, in_vlan,

                          out_vlan):

        """Prepare pop flow."""

        flow_mod = self._prepare_flow_mod(in_interface, out_interface)

        flow_mod['match']['dl_vlan'] = out_vlan

        if in_vlan:

            new_action = {'action_type': 'set_vlan', 'vlan_id': in_vlan}

            flow_mod['actions'].insert(0, new_action)

            new_action = {'action_type': 'push_vlan', 'tag_type': 'c'}

            flow_mod['actions'].insert(0, new_action)

        new_action = {"action_type": "pop_vlan"}

        flow_mod["actions"].insert(0, new_action)

        return flow_mod

class LinkProtection(EVCDeploy):