code: def login(self, username='admin', password='admin'):
          
          self.session = requests.Session()
          login = self.session.post(self.url+'login',
                                    data={'username': username,
                                          'password': password})
          if login.text == 'Ok.':
              self._is_authenticated = True
          else:
              return login.text
docs: Method to authenticate the qBittorrent Client.
  
          Declares a class attribute named ``session`` which
          stores the authenticated session if the login is correct.
          Else, shows the login error.
  
          :param username: Username.
          :param password: Password.
  
          :return: Response to login request to the API.