pocketmine\Server::broadcast PHP Method

    public function broadcast($message, $permissions)
    {
        /** @var CommandSender[] $recipients */
        $recipients = [];
        foreach (explode(";", $permissions) as $permission) {
            foreach ($this->pluginManager->getPermissionSubscriptions($permission) as $permissible) {
                if ($permissible instanceof CommandSender and $permissible->hasPermission($permission)) {
                    $recipients[spl_object_hash($permissible)] = $permissible;
                    // do not send messages directly, or some might be repeated
                }
            }
        }
        foreach ($recipients as $recipient) {
            $recipient->sendMessage($message);
        }
        return count($recipients);
    }