use copyValues instead of setting each param individually

Author: Alessandro Gagliardi

.gitignore

@@ -15,6 +15,7 @@ project/plugins/project/
 # Scala-IDE specific
 .scala_dependencies
 .worksheet
+.idea/
 
 # emacs stuff
 \#*\#

src/main/scala/com/high-performance-spark-examples/ml/CustomPipeline.scala

@@ -123,8 +123,7 @@ class SimpleIndexer(override val uid: String)
     val words = dataset.select(dataset($(inputCol)).as[String]).distinct
       .collect()
     val model = new SimpleIndexerModel(uid, words)
-    model.set(inputCol, $(inputCol))
-    model.set(outputCol, $(outputCol))
+    this.copyValues(model)
     model
   }
 }