* Automatically set maximize_evaluation_metrics if not explicitly given. * When custom_eval is set, require maximize_evaluation_metrics. * Update documents on early stop in XGBoost4J-Spark. * Fix code error.
* Automatically set maximize_evaluation_metrics if not explicitly given. * When custom_eval is set, require maximize_evaluation_metrics. * Update documents on early stop in XGBoost4J-Spark. * Fix code error.