Agree.  And then how about putting the `nil?` check into the `actual_ipn?` routine also for readability? Then the overall expression can become

```ruby
  post '/payments/ipn' do
    ipn = request.body.read
    if ipn_valid?(ipn)
      @@server_client.receive_ipn(ipn)
      response = @@server_client.ipn_response(ipn)
      url      = 'https://www.sandbox.paypal.com/cgi-bin/webscr'
      #used for testing
      #url = 'localhost:6810/receive_ipn/'
      @@server_client.send_paypal_response(url, response)
    end
  end
```