public function addResource(Bundle $bundle)
    {
        // if the config.yml file doesn't exist, don't even try.
        if (!file_exists($this->file)) {
            throw new \RuntimeException(sprintf('The target config file %s does not exist', $this->file));
        }

        $code = $this->getImportCode($bundle);

        $currentContents = file_get_contents($this->file);
        // Don't add same bundle twice
        if (false !== strpos($currentContents, $code)) {
            throw new \RuntimeException(sprintf('The %s configuration file from %s is already imported', $bundle->getServicesConfigurationFilename(), $bundle->getName()));
        }

        // find the "imports" line and add this at the end of that list
        $lastImportedPath = $this->findLastImportedPath($currentContents);
        if (!$lastImportedPath) {
            throw new \RuntimeException(sprintf('Could not find the imports key in %s', $this->file));
        }

        // find imports:
        $importsPosition = strpos($currentContents, 'imports:');
        // find the last import
        $lastImportPosition = strpos($currentContents, $lastImportedPath, $importsPosition);
        // find the line break after the last import
        $targetLinebreakPosition = strpos($currentContents, "\n", $lastImportPosition);

        $newContents = substr($currentContents, 0, $targetLinebreakPosition)."\n".$code.substr($currentContents, $targetLinebreakPosition);

        if (false === Generator::dump($this->file, $newContents)) {
            throw new \RuntimeException(sprintf('Could not write file %s ', $this->file));
        }
    }