org.apache.spark.mllib.tree.model.DecisionTreeModel has a predict method:
def predict(features: JavaRDD[Vector]): JavaRDD[Double]
The problem here is the generic type of the return type JAVARDD[Double] because its a scala Double and I would expect a java.lang.Double. (to be convenient e.g. with org.apache.spark.mllib.classification.ClassificationModel)
I wanted to extend the DecisionTreeModel and use it only for Binary Classification and wanted to implement the trait org.apache.spark.mllib.classification.ClassificationModel . But its not possible because the ClassificationModel already defines the predict method but with an return type JAVARDD[java.lang.Double].