opts.go
func ErrorReportingService(service string) Option {
	return func(sh *StackdriverHook) error {
		sh.errorReportingServiceName = service
		return nil
	}
}
func ErrorReportingService(service string) Option {
	return func(sh *StackdriverHook) error {
		sh.errorReportingServiceName = service
		return nil
	}
}
// ErrorReportingService is an option that defines the name of the service
// being tracked for Stackdriver error reporting.
// See:
// https://cloud.google.com/error-reporting/docs/formatting-error-messages