Apple_Push_API\MIME_Builder::add_content_from_file PHP Method

    public function add_content_from_file($filepath, $name = null)
    {
        // Get the contents of the file.
        $contents = '';
        // Try wp_remote_get first.
        if (defined('WPCOM_IS_VIP_ENV') && WPCOM_IS_VIP_ENV) {
            $request = vip_safe_wp_remote_get($filepath);
        } else {
            $request = wp_remote_get($filepath);
        }
        if (is_wp_error($request)) {
            // Try file_get_contents instead. This could be a local path.
            $contents = file_get_contents($filepath);
        } else {
            $contents = wp_remote_retrieve_body($request);
        }
        // Attempt to get the size
        $size = strlen($contents);
        // If this fails for some reason, try alternate methods
        if (empty($size)) {
            if (filter_var($filepath, FILTER_VALIDATE_URL)) {
                $headers = get_headers($filepath);
                foreach ($headers as $header) {
                    if (preg_match('/Content-Length: ([0-9]+)/i', $header, $matches)) {
                        $size = intval($matches[1]);
                    }
                }
            } else {
                // This will be the final catch for local files
                $size = filesize($filepath);
            }
        }
        // If the name wasn't specified, build it from the filename
        $filename = \Apple_News::get_filename($filepath);
        if (empty($name)) {
            $name = sanitize_key($filename);
        }
        return $this->build_attachment($name, $filename, $contents, $this->get_mime_type_for($filepath), $size);
    }

 /**
  * Parses the API response and checks for errors.
  * TODO The exporter has an abstracted article class. Should we have
  * something similar here? That way this method could live there.
  *
  * @param string $article
  * @param array $bundles
  * @param array $meta
  * @return string
  * @since 0.2.0
  */
 private function build_content($article, $bundles = array(), $meta = null)
 {
     $bundles = array_unique($bundles);
     $content = '';
     if ($meta) {
         $content .= $this->mime_builder->add_metadata($meta);
     }
     $content .= $this->mime_builder->add_json_string('my_article', 'article.json', $article);
     foreach ($bundles as $bundle) {
         $content .= $this->mime_builder->add_content_from_file($bundle);
     }
     $content .= $this->mime_builder->close();
     return $content;
 }