```ruby
cask 'sidplay' do
  version '4.0'
  sha256 'a7de546ba5a0b69365d57a8eff05a2820f81167ccd3a74e07ad3539e08a80bbd'

  # www.twinbirds.com/sidplay was verified as official when first introduced to the cask
  url "http://www.twinbirds.com/sidplay/SIDPLAY#{version.major}.zip"
  appcast 'http://www.sidmusic.org/sidplay/mac/sidplay_appcast.xml',
          checkpoint: 'b76e236f3dcca61d0a82c39d2e8449b7995c84e2f2546b1bd7958459c14cc186'
  name 'SIDPLAY'
  homepage 'http://www.sidmusic.org/sidplay/mac/'
  license :gpl

  app 'SIDPLAY.app'
end
```

Fix `url` stanza comment for SIDPLAY.
user
```ruby
cask 'sidplay' do
  version '4.0'
  sha256 'a7de546ba5a0b69365d57a8eff05a2820f81167ccd3a74e07ad3539e08a80bbd'

  # twinbirds.com/sidplay was verified as official when first introduced to the cask
  url "http://www.twinbirds.com/sidplay/SIDPLAY#{version.major}.zip"
  appcast 'http://www.sidmusic.org/sidplay/mac/sidplay_appcast.xml',
          checkpoint: 'b76e236f3dcca61d0a82c39d2e8449b7995c84e2f2546b1bd7958459c14cc186'
  name 'SIDPLAY'
  homepage 'http://www.sidmusic.org/sidplay/mac/'
  license :gpl

  app 'SIDPLAY.app'
end
```
assistant