public function write(AssetTarget $build, $content)
    {
        $ext = $build->ext();
        $path = $build->outputDir();

        if (!is_writable($path)) {
            throw new RuntimeException('Cannot write cache file. Unable to write to ' . $path);
        }
        $filename = $this->buildFileName($build);
        $success = file_put_contents($path . DIRECTORY_SEPARATOR . $filename, $content) !== false;
        $this->finalize($build);
        return $success;
    }