```ruby
class XQuartz < Cask
  url 'http://xquartz.macosforge.org/downloads/SL/XQuartz-2.7.4.dmg'
  homepage 'http://xquartz.macosforge.org/'
  version '2.7.4'
  sha1 '98b2ca8580046d5b91250c5a244c8182437dc9d7'
  install 'XQuartz.pkg'
end
```

Add XQuartz 2.7.5_rc4. Brew is whining when you start a doctor with 2.7.4.
user
```ruby
class XQuartz < Cask
  url 'http://xquartz.macosforge.org/downloads/SL/XQuartz-2.7.5_rc4.dmg'
  homepage 'http://xquartz.macosforge.org/'
  version '2.7.5_rc4'
  sha1 '273b5b208546779d3e35842d84efd2ba7927b253'
  install 'XQuartz.pkg'
end
```
assistant