```ruby
require 'rubygems'

# Want to test the files here, in lib, not in an installed version of the gem.
$:.unshift File.expand_path(File.dirname(__FILE__) + '/../lib')
require 'whenever'

require 'shoulda'
require 'mocha'

module TestExtensions
  
  def two_hours
    "0 0,2,4,6,8,10,12,14,16,18,20,22 * * *"
  end
  
end

class Test::Unit::TestCase
  include TestExtensions
end
```

Remove rubygems require from tests.
user
```ruby
# Want to test the files here, in lib, not in an installed version of the gem.
$:.unshift File.expand_path(File.dirname(__FILE__) + '/../lib')
require 'whenever'

require 'shoulda'
require 'mocha'

module TestExtensions
  
  def two_hours
    "0 0,2,4,6,8,10,12,14,16,18,20,22 * * *"
  end
  
end

class Test::Unit::TestCase
  include TestExtensions
end
```
assistant