"logging.googleapis.com/labels":{"hello":"world","hi":"universe"},"logging.googleapis.com/labels":{},

$ cat go.mod 
module example.com/m

go 1.14

require github.com/blendle/zapdriver v1.3.1

$ cat main.go 
package main

import (
        "log"

        "github.com/blendle/zapdriver"
)

func main() {
        logger, err := zapdriver.NewProduction()
        if err != nil {
                log.Fatal(err)
        }
        logger.Info(
                "Did something.",
                zapdriver.Labels(
                        zapdriver.Label("hello", "world"),
                        zapdriver.Label("hi", "universe"),
                ),
        )
}

$ go run .
{"severity":"INFO","timestamp":"2020-05-12T15:15:43.21090722-06:00","caller":"z/main.go:14","message":"Did something.","logging.googleapis.com/labels":{"hello":"world","hi":"universe"},"logging.googleapis.com/labels":{},"logging.googleapis.com/sourceLocation":{"file":"/home/tv/z/main.go","line":"14","function":"main.main"}}