protected function applyPostProcessorsToModel(Model $model)
    {
        foreach ($this->postProcessors as $processorClass => $parameters) {

            // if a processor class was added as a value instead of a key, it
            // does not have parameters
            if (is_numeric($processorClass)) {
                $processorClass = $parameters;
                $parameters     = null;
            }

            $processor = $this->makePostProcessor($processorClass, $parameters);

            $model = $processor->process($model);
        }

        return $model;
    }