import "code.cloudfoundry.org/lager" func main() { logger := lager.NewLogger("example-app") logger.RegisterSink(lager.NewWriterSink(os.Stdout, lager.DEBUG)) logger.Info("starting-up", lager.Data{"port": 8080}) // ... }In this code example, we create a Logger with the name "example-app". We then register a "sink", which in this case is a WriterSink that writes log messages to stdout with a minimum log level of DEBUG. Finally, we call the "Info" method on our Logger, passing in a log message with the key-value pair "port": 8080 attached as additional data. By adding this extra data to our log messages, we can provide more context to help with debugging and troubleshooting issues in our application. For example, if we see an error message like "Connection refused", we might be able to quickly identify the problem if we know which port the application was trying to connect to. Overall, the "code.cloudfoundry.org/lager" package library provides a powerful and flexible Logger system for Go applications, and the "WithData" method is a particularly useful feature for adding additional context to log messages.