The ellipsis is a powerful tool for extending functions. Unfortunately 
    this power comes at a cost: misspelled arguments will be silently ignored. 
    The ellipsis package provides a collection of functions to catch problems
    and alert the user.
c(
      person("Hadley", "Wickham", , "hadley@rstudio.com", role = c("aut", "cre")),
      person("RStudio", role = "cph")
    )
Hadley Wickham [aut, cre],
  RStudio [cph]