code: @CommandArgument
    public void passwd(
        @OptionArgument("username") String username,
        @OptionArgument("password") String password) {
  
      User user = users.get(username);
  
      if (user != null) {
        user.salt = passwd.generateSalt();
        user.hash = passwd.getEncryptedPassword(password, user.salt);
      } else {
        System.err.println(String.format("User '%s' does not exist", username));
      }
  
    }
docs: Resets the password of a user.
  @param username The username of the user whose password to reset.
  @param password The new password.