protected function loadConfiguration(InputInterface $input)
    {
        $loader = new ConfigurationLoader();

        if ($input->hasOption('config') && $file = $input->getOption('config')) {
            $configuration = $loader->loadFromFile($file);
        } else {
            
            if (null === $this->container) {
                throw new Exception('Unable to find the assets configuration from the container');
            }
            $configuration = $loader->loadFromContainer($this->container);
        }

        return $configuration;
    }