```ruby
# -*- coding: utf-8 -*-
require "rspec"
require 'tmpdir'
require "fileutils"
require File.join(File.dirname(__FILE__), '../lib/wrap_excel')

def create_tmpdir
  tmpdir = Dir.mktmpdir
  FileUtils.cp_r(File.join(File.dirname(__FILE__), 'data'), tmpdir)
  tmpdir + '/data'
end

def rm_tmp(tmpdir)
  FileUtils.remove_entry_secure(File.dirname(tmpdir))
end
```

Add caputure for test helper
user
```ruby
# -*- coding: utf-8 -*-
require "rspec"
require 'tmpdir'
require "fileutils"
require File.join(File.dirname(__FILE__), '../lib/wrap_excel')

def create_tmpdir
  tmpdir = Dir.mktmpdir
  FileUtils.cp_r(File.join(File.dirname(__FILE__), 'data'), tmpdir)
  tmpdir + '/data'
end

def rm_tmp(tmpdir)
  FileUtils.remove_entry_secure(File.dirname(tmpdir))
end

# This method is almost copy of wycats's implementation.
# http://pochi.hatenablog.jp/entries/2010/03/24
def capture(stream)
  begin
    stream = stream.to_s
    eval "$#{stream} = StringIO.new"
    yield
    result = eval("$#{stream}").string
  ensure
    eval("$#{stream} = #{stream.upcase}")
  end
  result
end
```
assistant