This function does its best attempt to take whatever you provide it and turn it into a grob. It is primarily meant to convert ggplot plots into grobs, but it will also take any grid object (grob), a recorded base R plot, a formula specifying a base R plot, a function that generates a base R plot, or a trellis object.
as_grob(plot, device = NULL)
The plot to convert
A function that creates an appropriate null device. See