Locator::is_feed( $file, $check_html = false )

143    public function is_feed($file, $check_html = false)144    {145        if ($file->method & \SimplePie\SimplePie::FILE_SOURCE_REMOTE) {146            $sniffer = $this->registry->create(Content\Type\Sniffer::class, [$file]);147            $sniffed = $sniffer->get_type();148            $mime_types = ['application/rss+xml', 'application/rdf+xml',149                                'text/rdf', 'application/atom+xml', 'text/xml',150                                'application/xml', 'application/x-rss+xml'];151            if ($check_html) {152                $mime_types[] = 'text/html';153            }154 155            return in_array($sniffed, $mime_types);156        } elseif ($file->method & \SimplePie\SimplePie::FILE_SOURCE_LOCAL) {157            return true;158        } else {159            return false;160        }161    }