source_example <- function(example, env = parent.frame(), disable_plots = TRUE) {
  ex_source <- readLines(system.file("examples", example, package = "RBesT", mustWork = TRUE))
  if (disable_plots) {
    ex_source <- grep("plot\\(", ex_source, value = TRUE, invert = TRUE)
  }
  suppressMessages(ex <- source(textConnection(ex_source),
    local = env, echo = FALSE, verbose = FALSE
  ))
  invisible(ex)
}