I guess, we can make this samples a bit more readable:

```ruby
context 'layout' do
  context 'when request is not XHR' do
    it 'renders application layout' do
    # ...
    end
  end

  context 'when request is XHR' do
    before { request.stub(:xhr? => true) }

    it 'does not render layout' do
    # ...
    end
  end
end
```

What do you think?