See containers. A cli_div container is special, because it may
add new themes, that are valid within the container.
cli_div(
  id = NULL,
  class = NULL,
  theme = NULL,
  .auto_close = TRUE,
  .envir = parent.frame()
)The id of the new container element, invisibly.
Element id, a string. If NULL, then a new id is generated
and returned.
Class name, sting. Can be used in themes.
A custom theme for the container. See themes.
Whether to close the container, when the calling
function finishes (or .envir is removed, if specified).
Environment to evaluate the glue expressions in. It is
also used to auto-close the container if .auto_close is TRUE.
d <- cli_div(theme = list(h1 = list(color = "cyan",
                                    "font-weight" = "bold")))
cli_h1("Custom title")
cli_end(d)
#>                                                                                 
#> Custom title                                                                    
By default a cli_div() is closed automatically when the calling
frame exits.
div <- function() {
  cli_div(class = "tmp", theme = list(.tmp = list(color = "yellow")))
  cli_text("This is yellow")
}
div()
cli_text("This is not yellow any more")
#> This is yellow                                                                  
#> This is not yellow any more