tracing

type Provider interface {
	// Middleware starts a root trace for each request.
	Middleware(log logger.Provider) echo.MiddlewareFunc

	StartSpan(c context.Context, operationName string) (opentracing.Span, context.Context)

	// Finsh span, primarily for mock purpose
	FinishSpan(span opentracing.Span)

	// Close io
	Close()
}