how to scale point size by area

Hi,

I have a case where I need to generate a scatter plot (via `geom_point(aes(..., size="value")`), where the areas (instead of the radii) of the points should scale by the given value.

For example, a point with the value of 40 should have area twice as a point with value of 20, not twice the radius. I tried setting it by playing with some parameters in `scale_size` and using`scale_size_area` but could not get what I expected. Honestly, the name `scale_size_area` felt like I found what I was looking for, but did not work as I expected and scaled by the radius (verified via inspecting in the browser).

Is there a way or a workaround to do so or is there a possible implementation error in the `scale_size_area()`?