'Reserve/Unreserve a fixed IP.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#reserve-or-release-a-fixed-ip'

def reserve_fixed_ip(self, fixed_ip, **kwargs):

    url = ('os-fixed-ips/%s/action' % fixed_ip)
    (resp, body) = self.post(url, json.dumps(kwargs))
    self.validate_response(schema.reserve_unreserve_fixed_ip, resp, body)
    return rest_client.ResponseBody(resp, body)
