To submit to CRAN we cannot use more than 2 threads in our examples/vignettes

R-package/R/xgb.cv.R

@@ -66,7 +66,7 @@
 #' @examples
 #' data(agaricus.train, package='xgboost')
 #' dtrain <- xgb.DMatrix(agaricus.train$data, label = agaricus.train$label)
-#' history <- xgb.cv(data = dtrain, nround=3, nfold = 5, metrics=list("rmse","auc"),
+#' history <- xgb.cv(data = dtrain, nround=3, nthread = 2, nfold = 5, metrics=list("rmse","auc"),
 #'                   "max.depth"=3, "eta"=1, "objective"="binary:logistic")
 #' print(history)
 #' @export