func ExampleMogrus() {
	l := logrus.New()

	clientOptions := options.Client().
	ApplyURI(os.Getenv("MONGO_CONNECTION")).
	SetServerAPIOptions(options.ServerAPI(options.ServerAPIVersion1))

	client, err := mongo.Connect(context.Background(), clientOptions)
	if err != nil {
		log.Fatalln(err)
	}

	opts := mogrus.Options{
		Collection: client.Database("logs").Collection("col"),
		// FireHook is a hook function called just before an
		// entry is logged to Mongo.
		FireHook: func(e mogrus.Entry) {
			fmt.Printf("%+v\n", e)
		},
		// ExpirationLevels allows for the customisation of expiry
		// time for each Logrus level by default entries do not expire.
		ExpirationLevels: mogrus.ExpirationLevels{
			logrus.DebugLevel: time.Second * 5,
			logrus.InfoLevel:  time.Second * 15,
			logrus.ErrorLevel: time.Second * 30,
		},
	}

	// Create the new Mogrus hook, returns an error if the
	// collection is nil.
	hook, err := mogrus.New(context.Background(), opts)
	if err != nil {
		log.Fatalln(err)
	}

	// Add the hook to the Logrus instance.
	l.AddHook(hook)

	l.Debug("Debug level")
	l.WithField("key", "value").Info("Info level")
	l.WithError(errors.NewInternal(errors.New("error"), "message", "op")).Error("Error level")
}

// Entry defines a singular entry sent to Mongo
// when a Logrus event is fired.
Entry struct {
	Level   string               `json:"level" bson:"level"`
	Time    time.Time            `json:"time" bson:"time"`
	Message string               `json:"message" bson:"message"`
	Data    map[string]any       `json:"data" bson:"data"`
	Error   *Error               `json:"error" bson:"error"`
	Expiry  map[string]time.Time `json:"expiry" bson:"expiry"`
}

// Error defines a custom Error for log entries, detailing
// the file line, errors are returned as strings instead
// of the stdlib error.
Error struct {
	Code      string `json:"code" bson:"code"`
	Message   string `json:"message" bson:"message"`
	Operation string `json:"operation" bson:"op"`
	Err       string `json:"error" bson:"err"`
	FileLine  string `json:"file_line" bson:"file_line"`
}