const maxSamplingRatePerMillion … func validateTracingConfig(samplingRate int) error { … } type tracingExporter … func newTracingExporter(ctx context.Context, cfg *Config) (*tracingExporter, error) { … } func (te *tracingExporter) Close(ctx context.Context) { … } func determineSampler(samplingRate int) tracesdk.Sampler { … } // As Tracing service Instance ID must be unique, it should // never use the empty default string value, it's set if // if it's a non empty string. func determineResourceWithIDKey(serviceInstanceID string) *resource.Resource { … }