tracing

type Option func(*options)

type Span interface {
	// End 结束Span
	End()
	// SetTag 设置Span标签
	SetTag(key string, value interface{})
	// SetError 设置Span错误
	SetError(err error)
	// SetStatus 设置状态
	SetStatus(code StatusCode, description string)
}

type StatusCode int

type Tracer interface {
	// Start 开始一个新的跟踪Span
	Start(ctx context.Context, operation string) (context.Context, Span)
}