将R自动安装SystemRequirements:对于尚未拥有该程序的用户

当用户使用SystemRequirements安装包时,如果他们还没有安装程序/包,那么R会安装它吗？

该CLIPR包是这个问题的很好的例子:https://github.com/mdlincoln/clipr/blob/master/DESCRIPTION.如果一个包声明了一个SystemRequirements:在'DESCRIPTION'文件中它是否会由R安装进行检查？

clipr描述文件

Package: clipr
Type: Package
Title: Read and Write from the System Clipboard
Version: 0.2.0.9000
Authors@R: c(
  person("Matthew", "Lincoln", email = "matthew.d.lincoln@gmail.com", role = c("aut", "cre")),
  person("Louis", "Maddox", role = "ctb"))
Description: Simple utility functions to read from and write to the Windows,
  OS X, and X11 clipboards.
Imports: utils
SystemRequirements: xclip (http://sourceforge.net/projects/xclip/) or xsel
  (http://www.vergenet.net/~conrad/software/xsel/) for accessing the X11
  clipboard
License: GPL-3
LazyData: TRUE
Suggests: testthat
URL: https://github.com/mdlincoln/clipr
BugReports: https://github.com/mdlincoln/clipr/issues

我已经参考了描述文件中的Writing R Extensions部分,但找不到我的问题的答案.