Add a new `residuals_plot`?

This example shows how to make a plot of multiple lines with a residual difference panel below the main plot.

Is this something that is common enough that we could have a dedicated function for creating it? For example, plopp.residual_plot(b, c, reference=a) would show 3 lines in the main panel and b-a and c-a in the residuals panel.

I guess it would be most useful if it could be used as a view in a graph of nodes, and not just a single purpose function. This would mean that it could be used in combination with a slider, where both the main panel and the residuals would update when moving the slider.