Append two celda_list objects (from S3 version of celda)

appendCeldaLists.R

appendCeldaList = function(celda.list.one, celda.list.two) {
  if (!is(celda.list.one, "celda_list") || !is(celda.list.two, "celda_list")) {
    stop("Both arguments must be of class \"celda_list\"")
  }
  if (celda.list.one$content.type != celda.list.two$content.type) {
    stop("Both arguments must have same content.type attribute")
  }
  if (celda.list.one$count.checksum != celda.list.two$count.checksum) {
    warning("count.checksum property on arguments do not match. Using checksum from first list.")
  }
  new.celda.list = list(run.params=rbind(celda.list.one$run.params, celda.list.two$run.params),
                        res.list=c(celda.list.one$res.list, celda.list.two$res.list),
                        content.type=celda.list.one$content.type,
                        count.checksum=celda.list.one$count.checksum)
  return(new.celda.list)
}