fix the merge

jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/Booster.java

@@ -350,7 +350,10 @@ public class Booster implements  Serializable {
   }
 
   /**
-   * get the dump of the model as a string array
+   * Save the model as byte array representation.
+   * Write these bytes to a file will give compatible format with other xgboost bindings.
+   *
+   * If java natively support HDFS file API, use toByteArray and write the ByteArray
    *
    * @param withStats Controls whether the split statistics are output.
    * @return dumped model information
@@ -367,9 +370,8 @@ public class Booster implements  Serializable {
   }
 
   /**
-   * get the dump of the model as a byte array
    *
-   * @return dumped model information
+   * @return the saved byte array.
    * @throws XGBoostError native error
    */
   public byte[] toByteArray() throws XGBoostError {

jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/DataBatch.java

@@ -57,7 +57,7 @@ class DataBatch {
     return b;
   }
 
-  static class BatchIterator implements Iterator<DataBatch>, Serializable {
+  static class BatchIterator implements Iterator<DataBatch> {
     private Iterator<LabeledPoint> base;
     private int batchSize;
 

jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/Rabit.java

@@ -10,7 +10,7 @@ import org.apache.commons.logging.LogFactory;
 /**
  * Rabit global class for synchronization.
  */
-public class Rabit implements Serializable {
+public class Rabit {
   private static final Log logger = LogFactory.getLog(DMatrix.class);
   //load native library
   static {