protected function loadPlugin($name, $file)
    {
        require_once $file;
        $className = sprintf('Zicht\Tool\Plugin\%s\Plugin', ucfirst(basename($name)));
        $class     = new \ReflectionClass($className);
        if (!$class->implementsInterface('Zicht\Tool\PluginInterface')) {
            throw new \UnexpectedValueException("The class $className is not a 'Zicht\\Tool\\PluginInterface'");
        }
        $this->plugins[$name] = $class->newInstance();
    }