Generating raport

I practice at ruby and I’ve done some example test case,now I would
like to
create test suite and generate report
can someone look at this code and explain me what’s wrong? I still get
message :

C:/Test/ruby/lib/ruby/site_ruby/1.8/test/unit/ui/reporter.rb:63:in
run': uninitialized constant Test::Unit::UI::Reporter::StringIO (NameError) from C:/Testy/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:ingem_original_require’
from
C:/Testy/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require’
from
C:/RadRails/plugins/org.rubypeople.rdt.testunit_0.8.0.604272100PRD/ruby/RemoteTestRunner.rb:260
thnx4help

require ‘watir’
include Watir

require ‘test/unit’
require ‘test/unit/ui/console/testrunner’
require ‘test/unit/ui/reporter’
require ‘fileutils’

class AttachClass<Test::Unit::TestCase
def test_example
#some code
end
end

begin
Test::Unit::UI::Console::TestRunner.new(AttachClass.suite).start
suite = Test::Unit::TestSuite.new
suite << AttachClass.suite
FileUtils.mkdir_p ‘build/report’
Test::Unit::UI::Reporter.run(suite, ‘build/report’,:html)
end

I answer myself

require ‘stringio’ is the statement fthe code needed