code: public static ParagraphVectors readParagraphVectors(File file) throws IOException {
          Word2Vec w2v = readWord2Vec(file);
  
          // and "convert" it to ParaVec model + optionally trying to restore labels information
          ParagraphVectors vectors = new ParagraphVectors.Builder(w2v.getConfiguration())
                  .vocabCache(w2v.getVocab())
                  .lookupTable(w2v.getLookupTable())
                  .resetModel(false)
                  .build();
  
          try (ZipFile zipFile = new ZipFile(file)) {
              // now we try to restore labels information
              ZipEntry labels = zipFile.getEntry("labels.txt");
              if (labels != null) {
                  InputStream stream = zipFile.getInputStream(labels);
                  try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, StandardCharsets.UTF_8))) {
                      String line;
                      while ((line = reader.readLine()) != null) {
                          VocabWord word = vectors.getVocab().tokenFor(decodeB64(line.trim()));
                          if (word != null) {
                              word.markAsLabel(true);
                          }
                      }
                  }
              }
          }
  
          vectors.extractLabels();
  
          return vectors;
      }
docs: This method restores ParagraphVectors model previously saved with writeParagraphVectors()
  
  @return