Set interface administrative state.

        Args:
            int_type (str): Type of interface. (gigabitethernet,
                tengigabitethernet, etc).
            name (str): Name of interface. (1/0/5, 1/0/10, etc).
            enabled (bool): Is proxy-arp enabled? (True, False)
            rbridge_id (str): rbridge-id for device. Only required when type is
                `ve`.
            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 `int_type`, `name`, or `state` is not passed.
            ValueError: if `int_type`, `name`, or `state` 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:
            ...         dev.interface.proxy_arp(int_type='tengigabitethernet',
            ...         name='225/0/12', enabled=True)
            ...         dev.interface.proxy_arp(int_type='tengigabitethernet',
            ...         name='225/0/12', enabled=False)
            ...         output = dev.interface.add_vlan_int('86')
            ...         output = dev.interface.ip_address(int_type='ve',
            ...         name='86', ip_addr='172.16.2.1/24', rbridge_id='225')
            ...         output = dev.interface.proxy_arp(int_type='ve',
            ...         name='86', enabled=True, rbridge_id='225')
            ...         output = dev.interface.proxy_arp(int_type='ve',
            ...         name='86', enabled=False, rbridge_id='225')

def proxy_arp(self, **kwargs):
        """Set interface administrative state.

        Args:
            int_type (str): Type of interface. (gigabitethernet,
                tengigabitethernet, etc).
            name (str): Name of interface. (1/0/5, 1/0/10, etc).
            enabled (bool): Is proxy-arp enabled? (True, False)
            rbridge_id (str): rbridge-id for device. Only required when type is
                `ve`.
            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 `int_type`, `name`, or `state` is not passed.
            ValueError: if `int_type`, `name`, or `state` 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:
            ...         dev.interface.proxy_arp(int_type='tengigabitethernet',
            ...         name='225/0/12', enabled=True)
            ...         dev.interface.proxy_arp(int_type='tengigabitethernet',
            ...         name='225/0/12', enabled=False)
            ...         output = dev.interface.add_vlan_int('86')
            ...         output = dev.interface.ip_address(int_type='ve',
            ...         name='86', ip_addr='172.16.2.1/24', rbridge_id='225')
            ...         output = dev.interface.proxy_arp(int_type='ve',
            ...         name='86', enabled=True, rbridge_id='225')
            ...         output = dev.interface.proxy_arp(int_type='ve',
            ...         name='86', enabled=False, rbridge_id='225')
        """
        int_type = kwargs.pop('int_type').lower()
        name = kwargs.pop('name')
        enabled = kwargs.pop('enabled', True)
        rbridge_id = kwargs.pop('rbridge_id', '1')
        callback = kwargs.pop('callback', self._callback)
        valid_int_types = ['gigabitethernet', 'tengigabitethernet',
                           'fortygigabitethernet', 'hundredgigabitethernet',
                           'port_channel', 've']

        if int_type not in valid_int_types:
            raise ValueError('`int_type` must be one of: %s' %
                             repr(valid_int_types))
        if not isinstance(enabled, bool):
            raise ValueError('`enabled` must be `True` or `False`.')

        method_name = 'interface_%s_ip_ip_config_proxy_arp' % int_type
        method_class = self._interface
        proxy_arp_args = dict(name=name)
        if int_type == 've':
            method_name = "rbridge_id_%s" % method_name
            method_class = self._rbridge
            proxy_arp_args['rbridge_id'] = rbridge_id
            if not pynos.utilities.valid_vlan_id(name):
                raise InvalidVlanId("`name` must be between `1` and `8191`")
        elif not pynos.utilities.valid_interface(int_type, name):
            raise ValueError('`name` must be in the format of x/y/z for '
                             'phyiscal interfaces or x for port channel.')

        proxy_arp = getattr(method_class, method_name)
        config = proxy_arp(**proxy_arp_args)
        if not enabled:
            config.find('.//*proxy-arp').set('operation', 'delete')
        try:
            return callback(config)
        # TODO: Catch existing 'no proxy arp'
        # This is in place because if proxy arp is already disabled,
        # `ncclient` will raise an error if you try to disable it again.
        except AttributeError:
            return None