code: def add_username(user, apps):
      
      if not user:
          return None
  
      apps = [a for a in apps if a.instance == user.instance]
  
      if not apps:
          return None
  
      from toot.api import verify_credentials
      creds = verify_credentials(apps.pop(), user)
  
      return User(user.instance, creds['username'], user.access_token)
docs: When using broser login, username was not stored so look it up