# File spec/spider/spider_instance_spec.rb, line 381
  def callback_arguments_on(code)
    si = SpiderInstance.new('http://foo.com/' => ['http://example.com/'])
    si.stubs(:allowed?).returns(true)
    si.stubs(:generate_next_urls).returns([])
    si.on(code) do |a_url, resp, prior_url|
      a_url.should == 'http://example.com/'
      resp.should_not be_nil
      prior_url.should == 'http://foo.com/'
    end
    si.start!
  end