public default <K, V> JavaPairRDD<K, V> repartitionJavaPairRDD(final String repartitionString, JavaPairRDD<K, V> graphRDD) {
        JavaPairRDD<K, V> javaPairRDD = graphRDD;
        final int repartition = null == repartitionString ? -1 : Integer.parseInt(repartitionString);
        if (repartition > 0) {
            javaPairRDD = javaPairRDD.repartition(repartition);
        }
        return javaPairRDD;
    }
Allow users to customize the RDD partitions to reduce HDFS small files
spark-gremlin/src/main/java/org/apache/tinkerpop/gremlin/spark/structure/io/OutputRDD.java