## trimws was added in R 2.3.0.  If we're using a previous version of
## R we need to define it.
if (!exists("trimws", mode = "function")) {
  trimws <- function(s) {
    s <- sub(pattern = "^[[:blank:]]+", replacement = "", x = s)
    s <- sub(pattern = "[[:blank:]]+$", replacement = "", x = s)
    s
  }
}