Creates a bonded port.

        :param name: Port name to be created
        :param ifaces: List of interfaces containing at least 2 interfaces
        :param bond_mode: Bonding mode (active-backup, balance-tcp
                          or balance-slb)
        :param lacp: LACP mode (active, passive or off)

def add_bond(self, name, ifaces, bond_mode=None, lacp=None):
        """
        Creates a bonded port.

        :param name: Port name to be created
        :param ifaces: List of interfaces containing at least 2 interfaces
        :param bond_mode: Bonding mode (active-backup, balance-tcp
                          or balance-slb)
        :param lacp: LACP mode (active, passive or off)
        """
        assert len(ifaces) >= 2

        options = ''
        if bond_mode:
            options += 'bond_mode=%(bond_mode)s' % locals()
        if lacp:
            options += 'lacp=%(lacp)s' % locals()

        command_add = ovs_vsctl.VSCtlCommand(
            'add-bond', (self.br_name, name, ifaces), options)
        self.run_command([command_add])