package main

import (
 "fmt"
 "time"
)

var m map[string]time.Duration

func main() {
 start := time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC)
 end := time.Date(2000, 1, 1, 12, 0, 0, 0, time.UTC)

 difference := end.Sub(start)
 
 m = make(map[string]time.Duration)
 m["Bell Labs"] = difference
 fmt.Println(m["Bell Labs"])
}

updOptions := options.FindOneAndReplace()
updOptions.SetUpsert(true)
updOptions.SetReturnDocument(options.After)

filter := bson.M{
    "data":   bson.M{"$eq": val},
}


updateResult := collection.FindOneAndReplace(ctx, filter, item, updOptions)