内容安全中枢的网络弹性部署保障体系多云网关矩阵多层防线风险联动升级方案

```python def register_user(username, password): """ Registers a new user. Args: username (str): The username of the new user. password (str): The password of the new user. Raises: ValueError: If the username is already taken. """ Check if the username is already taken if username in users: raise ValueError("Username already taken") Create a new user object user = User(username, password) Add the new user to the list of users users.append(user) ``` J影音a: ```j影音a public void registerUser(String username, String password) { // Check if the username is already taken if (users.containsKey(username)) { throw new IllegalArgumentException("Username already taken"); } // Create a new user object User user = new User(username, password); // Add the new user to the map of users users.put(username, user); } ``` C: ```csharp public void RegisterUser(string username, string password) { // Check if the username is already taken if (users.ContainsKey(username)) { throw new ArgumentException("Username already taken"); } // Create a new user object User user = new User(username, password); // Add the new user to the dictionary of users users.Add(username, user); } ``` PHP: ```php public function registerUser(string $username, string $password) { // Check if the username is already taken if (isset($this->users[$username])) { throw new Exception("Username already taken"); } // Create a new user object $user = new User($username, $password); // Add the new user to the array of users $this->users[$username] = $user; } ```