This overrides the default ggplot print method to add brackets automatically
# S3 method for gg
print(x, newpage = is.null(vp), vp = NULL, ...)Invisibly returns the input ggplot object (classes "gg" and "ggplot").
Called for its side effects: rendering the plot to the current graphics device with the vbracket legend overlay if present.
A ggplot object
Draw on new page (default TRUE)
Viewport to draw in
Additional arguments