Makie: plotting the sample arrow for `arrows!()`?

I’ve just started to use arrows!(). I’ve find it straightforward to use. Now, I’m trying to find a way to plot the sample arrow. See the image, which I plotted using a different program, at the bottom of this message. Below the bottom x axis, near the lower right corner, there is the sample arrow: the length of that arrow represents a speed of 10 m/s.

I’ve looked at the manual of arrows!() function and I searched the Internet and then this forum, but I haven’t found a mention to the sample arrow. Is there an example somewhere?

The text has Label() and text!(). Does the arrow has counterparts? Or, perhaps does the sample arrow belong to the “legend” facility?

I often want to plot the sample arrow within the arrows plot if I there is ample empty space. The image below actually shows wind vectors on the oceans. That means that you may want to plot the sample arrow in South America or Africa. (Similarly, you sometimes want to place your legend in an empty portion of a line graph.)