```ruby
require 'sinatra/base'

class MockInhalt < Sinatra::Base
  get '/' do
    'Hello MockInhalt!'
  end

  # start the server if ruby file executed directly
  run! if app_file == $0
end

```

Set 8080 as default listening port and removed the call to 'run'.
user
```ruby
require 'sinatra/base'

class MockInhalt < Sinatra::Base
  set :port, 8080

  get '/' do
    'Hello MockInhalt!'
  end
end

```
assistant