fix: `addLayer` not including trees original classes

DESCRIPTION

 Type: Package
 Package: RFSurrogates
 Title: Surrogate Minimal Depth Variable Importance
-Version: 0.3.3.9004
+Version: 0.3.3.9005
 Authors@R: c(
     person("Stephan", "Seifert", , "stephan.seifert@uni-hamburg.de", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0003-2567-5728")),

R/addLayer.R

@@ -23,11 +23,11 @@ addLayer <- function(trees, num.threads = 1) {
     stop("`trees` must be a `getTreeranger` `RangerTrees` object.")
   }
 
-  trees <- parallel::mclapply(trees, add_layer_to_tree, mc.cores = num.threads)
+  layer.trees <- parallel::mclapply(trees, add_layer_to_tree, mc.cores = num.threads)
 
-  class(trees) <- c(class(trees), "LayerTrees")
+  class(layer.trees) <- c(class(trees), "LayerTrees")
 
-  return(trees)
+  return(layer.trees)
 }
 
 #' Internal function