get_spam_domain_list()

        public function get_spam_domain_list(){
            $spam_domain_json_file = get_template_directory() . '/inc/data/spam_domain_list.txt';

            $spam_domain_list = nebula()->transient('nebula_spam_domain_list', function($data){
                $response = $this->remote_get('https://raw.githubusercontent.com/matomo-org/referrer-spam-list/master/spammers.txt'); //Watch for this to change from "master" to "main" (if ever)
                if ( !is_wp_error($response) ){
                    $spam_domain_list = $response['body'];
                }

                //If there was an error or empty response, try my GitHub repo
                if ( is_wp_error($response) || empty($spam_domain_list) ){ //This does not check availability because it is the same hostname as above.
                    $response = $this->remote_get('https://raw.githubusercontent.com/chrisblakley/Nebula/main/inc/data/spam_domain_list.txt');
                    if ( !is_wp_error($response) ){
                        $spam_domain_list = $response['body'];
                    }
                }

                //If either of the above remote requests received data, update the local file and store the data in a transient for 36 hours
                if ( !is_wp_error($response) && !empty($spam_domain_list) ){
                    WP_Filesystem();
                    global $wp_filesystem;
                    $wp_filesystem->put_contents($data['spam_domain_json_file'], $spam_domain_list);

                    return $spam_domain_list;
                }
            }, array('spam_domain_json_file' => $spam_domain_json_file), HOUR_IN_SECONDS*36);

            //If neither remote resource worked, get the local file
            if ( empty($spam_domain_list) ){
                WP_Filesystem();
                global $wp_filesystem;
                $spam_domain_list = $wp_filesystem->get_contents($spam_domain_json_file);
            }

            //If one of the above methods worked, parse the data.
            if ( !empty($spam_domain_list) ){
                $spam_domain_array = array();
                foreach( explode("\n", $spam_domain_list) as $line ){
                    if ( !empty($line) ){
                        $spam_domain_array[] = $line;
                    }
                }
            } else {
                $this->ga_send_exception('(Security) spammers.txt was not available!', false);
            }

            //Add manual and user-added spam domains
            $manual_nebula_spam_domains = array(
                'bitcoinpile.com',
            );
            $all_spam_domains = apply_filters('nebula_spam_domains', $manual_nebula_spam_domains);

            return array_merge($spam_domain_array, $all_spam_domains);
        }