code: public static void saveMapFileSequences(String path, JavaRDD<List<List<Writable>>> rdd) {
          saveMapFileSequences(path, rdd, DEFAULT_MAP_FILE_INTERVAL, null);
      }
docs: Save a {@code JavaRDD<List<List<Writable>>>} to a Hadoop {@link org.apache.hadoop.io.MapFile}. Each record is
  given a <i>unique and contiguous</i> {@link LongWritable} key, and values are stored as
  {@link SequenceRecordWritable} instances.<br>
  <b>Note 1</b>: If contiguous keys are not required, using a sequence file instead is preferable from a performance
  point of view. Contiguous keys are often only required for non-Spark use cases, such as with
  {@link org.datavec.hadoop.records.reader.mapfile.MapFileSequenceRecordReader}<br>
  <b>Note 2</b>: This use a MapFile interval of {@link #DEFAULT_MAP_FILE_INTERVAL}, which is usually suitable for
  use cases such as {@link org.datavec.hadoop.records.reader.mapfile.MapFileSequenceRecordReader}. Use
  {@link #saveMapFileSequences(String, JavaRDD, int, Integer)} or {@link #saveMapFileSequences(String, JavaRDD, Configuration, Integer)}
  to customize this. <br>
  <p>
  Use {@link #restoreMapFileSequences(String, JavaSparkContext)} to restore values saved with this method.
  
  @param path Path to save the MapFile
  @param rdd  RDD to save
  @see #saveMapFileSequences(String, JavaRDD)
  @see #saveSequenceFile(String, JavaRDD)