code: def UpdateUserCredentials(client_id, client_secret, refresh_token,
                            adwords_manager_cid, developer_token):
    
    app_user = AppUser.query(AppUser.user == users.get_current_user()).fetch()[0]
  
    app_user.client_id = client_id
    app_user.client_secret = client_secret
    app_user.refresh_token = refresh_token
    app_user.adwords_manager_cid = adwords_manager_cid
    app_user.developer_token = developer_token
  
    app_user.put()
docs: Update the credentials associated with application user.
  
    Args:
      client_id: str Client Id retrieved from the developer's console.
      client_secret: str Client Secret retrieved from the developer's console.
      refresh_token: str Refresh token generated with the above client id/secret.
      adwords_manager_cid: str Customer Id for the AdWords manager account.
      developer_token: str Developer Token for the AdWords account.