```ruby
require File.dirname(__FILE__) + '/../spec_helper'
```

Add a minimal spec for the 'undef' keyword
user
```ruby
require File.dirname(__FILE__) + '/../spec_helper'

class UndefSpecClass
  def meth=(other);nil;end
end

describe "The undef keyword" do
  it "should undefine 'meth='" do
    obj = UndefSpecClass.new
    (obj.meth = 5).should == 5
    class UndefSpecClass
      undef meth=
    end
    should_raise(NoMethodError) { obj.meth = 5 }
  end
end
```
assistant