编辑从名称空间加载的函数时出现问题

Question

我想从mlr软件包中临时修改 selectFeatures 功能。但是，当我尝试执行此操作（使用 assignInNamespace 函数）时会出错，因为 selectFeatures 从未按我的意愿进行修改（请参见下面的代码）。发生了什么事？

注意： reassignInPackage 函数也没用

library(mlr)

assignInNamespace("selectFeatures",function(){},"mlr")
getFromNamespace("selectFeatures","mlr") #selectFeatures in mlr namespace seems modified
selectFeatures #Shows the initial selectFeatures function !
environment(selectFeatures) #Shows that selectFeatures is in mlr namespace, so it should be modified !