public static function post_install(PackageEvent $event)
 {
     $operation = $event->getOperation();
     $reason = $operation->getReason();
     if ($reason instanceof Rule) {
         switch ($reason->getReason()) {
             case Rule::RULE_PACKAGE_CONFLICT:
             case Rule::RULE_PACKAGE_SAME_NAME:
             case Rule::RULE_PACKAGE_REQUIRES:
                 $composer_error = $reason->getPrettyString($event->getPool());
                 break;
         }
         if (!empty($composer_error)) {
             WP_CLI::log(sprintf(" - Warning: %s", $composer_error));
         }
     }
 }