code: public void fitLabelledDocuments(JavaRDD<LabelledDocument> documentsRdd) {
  
          validateConfiguration();
  
          broadcastEnvironment(new JavaSparkContext(documentsRdd.context()));
  
          JavaRDD<Sequence<VocabWord>> sequenceRDD =
                          documentsRdd.map(new DocumentSequenceConvertFunction(configurationBroadcast));
  
          super.fitSequences(sequenceRDD);
      }
docs: This method builds ParagraphVectors model, expecting JavaRDD<LabelledDocument>.
  It can be either non-tokenized documents, or tokenized.
  
  @param documentsRdd