'Creates a consistency group.'

def create_consistencygroup(self, volume_types, **kwargs):

    post_body = {'volume_types': volume_types}
    if kwargs.get('availability_zone'):
        post_body['availability_zone'] = kwargs.get('availability_zone')
    if kwargs.get('name'):
        post_body['name'] = kwargs.get('name')
    if kwargs.get('description'):
        post_body['description'] = kwargs.get('description')
    post_body = json.dumps({'consistencygroup': post_body})
    (resp, body) = self.post('consistencygroups', post_body)
    body = json.loads(body)
    self.expected_success(http_client.ACCEPTED, resp.status)
    return rest_client.ResponseBody(resp, body)
