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

R-package/man/xgb.cv.Rd

@@ -78,7 +78,7 @@ This function only accepts an \code{xgb.DMatrix} object as the input.
 \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)
 }