'Create region.
For a full list of available parameters, please refer to the official
API reference:
http://developer.openstack.org/api-ref/identity/v3/index.html#create-region'

def create_region(self, region_id=None, **kwargs):

    if (region_id is not None):
        method = self.put
        url = ('regions/%s' % region_id)
    else:
        method = self.post
        url = 'regions'
    req_body = json.dumps({'region': kwargs})
    (resp, body) = method(url, req_body)
    self.expected_success(201, resp.status)
    body = json.loads(body)
    return rest_client.ResponseBody(resp, body)
