'Add a fixed IP to server instance.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#add-associate-fixed-ip-addfixedip-action'

def add_fixed_ip(self, server_id, **kwargs):

    return self.action(server_id, 'addFixedIp', **kwargs)
