You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: stamps_test.rb
    path of file: ./repos/workarea/core/vendor/active_shipping/test/unit/carriers
    
    the code of the file until where you have to start completion: require 'test_helper'

class StampsTest < ActiveSupport::TestCase
  include ActiveShipping::Test::Fixtures

  def setup
    @carrier = Stamps.new(integration_id: 'i', username: 'u', password: 'p')
    @items   = [{ sku: 'AF0001', quantity: 1 }, { sku: 'AF0002', quantity: 2 }]
    @a
    
  def test_authenticator_renewal
    fixtures = [
      @authentication_response,
      xml_fixture('stamps/get_account_info_response'),
      xml_fixture('stamps/expired_authenticator_response'),
      @authentication_response,
      xml_fixture('stamps/get_account_info_response')
    ]

    @carrier.expects(:ssl_post).times(5).returns(*fixtures)

    # The first call gets initial authenticator, second call receives
    # expired authenticator
    @carrier.account_info
    account_info = @carrier.account_info

    assert_equal 'ActiveShipping::StampsAccountInfoResponse', account_info.class.name
  end