```ruby
class XamarinStudio < Cask
  url 'http://download.xamarin.com/studio/Mac/XamarinStudio-4.2.3.60-60.dmg'
  homepage 'http://xamarin.com/studio'
  version '4.2.3'
  sha256 'e95bd713b8790990c769dc9cb7ca49eeb52c3393f2f882a91e3fed37b2a20f65'
  link 'Xamarin Studio.app'
end
```

Update Xamarin Studio to v4.2.4
user
```ruby
class XamarinStudio < Cask
  url 'http://download.xamarin.com/studio/Mac/XamarinStudio-4.2.4.35-0.dmg'
  homepage 'http://xamarin.com/studio'
  version '4.2.4'
  sha256 'd5c2519822b134034d9d7ef6aad0c3311ca9fabc9d97b1069223125dca5ce1f1'
  link 'Xamarin Studio.app'
end
```
assistant