private function queueOperation($http_verb, $id, $method, $args = null)
    {
        $operation = array(
            'operation_id' => $id,
            'method'       => $http_verb,
            'path'         => $method,
        );

        if ($args) {
            if ($http_verb == 'GET') {
                $key             = 'params';
                $operation[$key] = $args;
            } else {
                $key             = 'body';
                $operation[$key] = json_encode($args);
            }
        }

        $this->operations[] = $operation;
    }