docs: protected void initialize() {
          log.info("Building Huffman tree for source graph...");
          int nVertices = sourceGraph.numVertices();
          //int[] degrees = new int[nVertices];
          //for( int i=0; i<nVertices; i++ )
          // degrees[i] = sourceGraph.getVertexDegree(i);
          /*
          for (int y = 0; y < nVertices; y+= 20) {
              int[] copy = Arrays.copyOfRange(degrees, y, y+20);
              System.out.println("D: " + Arrays.toString(copy));
          }
          */
          //        GraphHuffman huffman = new GraphHuffman(nVertices);
          //        huffman.buildTree(degrees);
  
          log.info("Transferring Huffman tree info to nodes...");
          for (int i = 0; i < nVertices; i++) {
              T element = sourceGraph.getVertex(i).getValue();
              element.setElementFrequency(sourceGraph.getConnectedVertices(i).size());
  
              if (vocabCache != null)
                  vocabCache.addToken(element);
          }
  
          if (vocabCache != null) {
              Huffman huffman = new Huffman(vocabCache.vocabWords());
              huffman.build();
              huffman.applyIndexes(vocabCache);
          }
      }