class StatelyDB::Common::Auth::AuthTokenProvider::Actor

def refresh_token
  Async do
    # we use an Async::Condition to dedupe multiple requests here
    # if the condition exists, we wait on it to complete
    # otherwise we create a condition, make the request, then signal the condition with the result
    # If there is an error then we signal that instead so we can raise it for the waiters.
    if @pending_refresh.nil?
      begin
        @pending_refresh = Async::Condition.new
        new_access_token = refresh_token_impl
        # now broadcast the new token to any waiters
        @pending_refresh.signal(new_access_token)
        new_access_token
      rescue StandardError => e
        @pending_refresh.signal(e)
        raise e
      ensure
        # delete the condition to restart the process
        @pending_refresh = nil
      end
    else
      res = @pending_refresh.wait
      # if the refresh result is an error, re-raise it.
      # otherwise return the token
      raise res if res.is_a?(StandardError)
      res
    end
  end
end