plot_add_scheme() is a generic used to apply a Scheme (or a Schemes
container) to a plot object. This allows schemes to update or modify
the plot's appearance or behavior according to their configuration.
plot_add_scheme(plot, scheme, ...)The modified plot object.
A plot object, typically a ggplot.
A Scheme or Schemes object to apply.
Additional arguments passed to specific methods.
By default When a Schemes object is passed, each individual Scheme is
applied in sequence via its respective plot_add_scheme() method.