<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def evpn_afi_peer_activate(self, **kwargs):
 """ Activate EVPN AFI for a peer. Args: ip_addr (str):
 IP Address of BGP neighbor. rbridge_id (str):
 The rbridge ID of the device on which BGP will be configured in a VCS fabric. delete (bool):
 Deletes the neighbor if `delete` is ``True``. Deactivate get (bool):
 Get config instead of editing config. (True, False) 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: None Examples: """

        peer_ip = kwargs.pop('peer_ip')
        callback = kwargs.pop('callback', self._callback)
        evpn_activate = getattr(self._rbridge,
                                'rbridge_id_router_router_bgp_address_family_'
                                'l2vpn_evpn_neighbor_evpn_neighbor_ipv4_'
                                'activate')
        args = dict(evpn_neighbor_ipv4_address=peer_ip, ip_addr=peer_ip,
                    rbridge_id=kwargs.pop('rbridge_id'),
                    afi='evpn')
        evpn_activate = evpn_activate(**args)
        if kwargs.pop('delete', False):
            evpn_activate.find('.//*activate').set('operation', 'delete')
        if kwargs.pop('get', False):
            return callback(evpn_activate, handler='get_config')
        return callback(evpn_activate)