code: public static void saveSequenceFileSequences(String path, JavaRDD<List<List<Writable>>> rdd) {
          saveSequenceFileSequences(path, rdd, null);
      }
docs: Save a {@code JavaRDD<List<List<Writable>>>} to a Hadoop {@link org.apache.hadoop.io.SequenceFile}. Each record
  is given a unique (but noncontiguous) {@link LongWritable} key, and values are stored as {@link SequenceRecordWritable} instances.
  <p>
  Use {@link #restoreSequenceFileSequences(String, JavaSparkContext)} to restore values saved with this method.
  
  @param path Path to save the sequence file
  @param rdd  RDD to save
  @see #saveSequenceFile(String, JavaRDD)
  @see #saveMapFileSequences(String, JavaRDD)