```ruby
class Opera < Cask
  url 'http://get.geo.opera.com/pub/opera/mac/1215/Opera_12.15_Setup_Intel.dmg'
  homepage 'http://www.opera.com/'
  version '12.15'
  sha1 '5889d940e3c61eb92ea4045909e6def50e1839ba' 
  link 'Opera.app'
end
```

Update Opera to latest version
user
```ruby
class Opera < Cask
  url 'http://get.geo.opera.com/pub/opera/desktop/15.0.1147.132/mac/Opera_15.0.1147.132_Setup.dmg'
  homepage 'http://www.opera.com/'
  version '15.0.1147.132'
  sha1 '2f921efa23adf3f09672da6b720863c5b15579fa'
  link 'Opera.app'
end
```
assistant