Remove a port channel interface.

        Args:
            port_int (str): port-channel number (1, 2, 3, etc).
            callback (function): A function executed upon completion of the
                 method.  The only parameter passed to `callback` will be the
                 ``ElementTree`` `config`.

        Returns:
            Return value of `callback`.

        Raises:
            KeyError: if `port_int` is not passed.
            ValueError: if `port_int` is invalid.

        Examples:
            >>> import pynos.device
            >>> switches = ['10.24.39.211', '10.24.39.203']
            >>> auth = ('admin', 'password')
            >>> for switch in switches:
            ...     conn = (switch, '22')
            ...     with pynos.device.Device(conn=conn, auth=auth) as dev:
            ...         output = dev.interface.channel_group(name='225/0/20',
            ...         int_type='tengigabitethernet',
            ...         port_int='1', channel_type='standard', mode='active')
            ...         output = dev.interface.remove_port_channel(
            ...         port_int='1')

def remove_port_channel(self, **kwargs):
        """
        Remove a port channel interface.

        Args:
            port_int (str): port-channel number (1, 2, 3, etc).
            callback (function): A function executed upon completion of the
                 method.  The only parameter passed to `callback` will be the
                 ``ElementTree`` `config`.

        Returns:
            Return value of `callback`.

        Raises:
            KeyError: if `port_int` is not passed.
            ValueError: if `port_int` is invalid.

        Examples:
            >>> import pynos.device
            >>> switches = ['10.24.39.211', '10.24.39.203']
            >>> auth = ('admin', 'password')
            >>> for switch in switches:
            ...     conn = (switch, '22')
            ...     with pynos.device.Device(conn=conn, auth=auth) as dev:
            ...         output = dev.interface.channel_group(name='225/0/20',
            ...         int_type='tengigabitethernet',
            ...         port_int='1', channel_type='standard', mode='active')
            ...         output = dev.interface.remove_port_channel(
            ...         port_int='1')
        """
        port_int = kwargs.pop('port_int')
        callback = kwargs.pop('callback', self._callback)

        if re.search('^[0-9]{1,4}$', port_int) is None:
            raise ValueError('%s must be in the format of x for port channel '
                             'interfaces.' % repr(port_int))

        port_channel = getattr(self._interface, 'interface_port_channel_name')
        port_channel_args = dict(name=port_int)

        config = port_channel(**port_channel_args)

        delete_channel = config.find('.//*port-channel')
        delete_channel.set('operation', 'delete')

        return callback(config)