code: func (tc Conn) newChildSpan(ctx context.Context) opentracing.Span {
  	p := tc.params
  	span, _ := opentracing.StartSpanFromContext(ctx, "redis.command")
  	span.SetTag(ext.ServiceName, p.config.serviceName)
  	span.SetTag(ext.SpanType, "cache")
  	span.SetTag("out.network", p.network)
  	span.SetTag("out.port", p.port)
  	span.SetTag("out.host", p.host)
  
  	return span
  }
docs: // newChildSpan creates a span inheriting from the given context. It adds to the span useful metadata about the traced Redis connection