code: public function save(array $options)
      {
          $resolver = new OptionsResolver();
          $this->configureOptions($resolver);
          $this->options = $resolver->resolve($options);
  
          $request = $this->options["request"];
          $password = $request->get('password');
          $user = $this->fetchUser($this->options['security'], $this->options['configuration_handler']);
  
          $factory = $this->options['encoder_factory'];
          $encoder = $factory->getEncoder($user);
          $salt = base_convert(sha1(uniqid(mt_rand(), true)), 16, 36);
          $password = $encoder->encodePassword($password, $salt);
  
          $userName = "admin";
          $usersFile = $this->options['configuration_handler']->usersDir() . '/users.json';
          $users = json_decode(FilesystemTools::readFile($usersFile), true);
          $user = $users[$userName];
          $user["password"] = $password;
          $user["salt"] = $salt;
          $users[$userName] = $user;
          FilesystemTools::writeFile($usersFile, json_encode($users));
      }
docs: Implements the action to update the user information
  @param array $options
  
  @return \Symfony\Component\HttpFoundation\Response