code: func (manager *Manager) GetValidatedPhoneNumbersByUsernames(usernames []string) (validatedPhonenumbers []ValidatedPhonenumber, err error) {
  	mgoCollection := db.GetCollection(manager.session, mongoValidatedPhonenumbers)
  	qry := bson.M{
  		"username": bson.M{
  			"$in": usernames,
  		},
  	}
  	err = mgoCollection.Find(qry).All(&validatedPhonenumbers)
  	return
  }
docs: // Returns all validated phone numbers for every username