具有命名的ParamSets的mlr makeModelMultiplexerParamSet

makeModelMultiplexerParamSet可以提供mlr R包状态的文档，名为ParamSets，以消除将哪些参数传递给哪个学习者的歧义，但是该文档未包含如何执行此操作的示例。我已经尝试了一些方法（例如下面显示的内容），但是可以makeModelMultiplexerParamSet上班了。任何帮助，将不胜感激。

base.learners = list(
  makeLearner("classif.ksvm",  predict.type = 'prob'),
  makeLearner("classif.randomForest",  predict.type = 'prob', ntree=500L),
  makeLearner('classif.xgboost', predict.type = 'prob', nthread=2, nrounds=1000L)
)
lrn = makeModelMultiplexer(base.learners)

# learners
ps = list(
  classif.randomForest = makeParamSet(makeIntegerParam("mtry", lower=1L, upper=100L)),
  classif.ksvm = makeParamSet(makeNumericParam("C", lower = 0.01, upper = 0.1),
                   makeNumericParam("sigma", lower = 0.005, upper = 0.5, trafo = function(x) 2^x)),            
  classif.xgboost = makeParamSet(makeIntegerParam("max_depth", lower=1L, upper=100L),
                      makeNumericParam("eta", lower=0.05, upper=0.5),
                      makeNumericParam("gamma", lower=0, upper=1))
)

ps = makeModelMultiplexerParamSet(lrn, ps)

错误：

Error in FUN(X[[i]], ...): List args has element of wrong type list at position 1. Should be: ParamSet
Traceback:
1. makeModelMultiplexerParamSet(lrn, ps)
2. checkListElementClass(args, "ParamSet")
3. lapply(seq_along(xs), function(i) {
 .     x = xs[[i]]
 .     if (!(is(x, cl))) 
 .         stop("List ", s, " has element of wrong type ", class(x)[1L], 
 .             " at position ", i, ". Should be: ", cl)
 . })
4. FUN(X[[i]], ...)
5. stop("List ", s, " has element of wrong type ", class(x)[1L], 
 .     " at position ", i, ". Should be: ", cl)