docs: private Instance readDenseInstanceSparse() {
          //Returns a dense instance
          Instance instance = newDenseInstance(this.instanceInformation.numAttributes());
          //System.out.println(this.instanceInformation.numAttributes());
          int numAttribute;
          try {
              //while (streamTokenizer.ttype != StreamTokenizer.TT_EOF) {
              streamTokenizer.nextToken(); // Remove the '{' char
              //For each line
              while (streamTokenizer.ttype != StreamTokenizer.TT_EOL
                      && streamTokenizer.ttype != StreamTokenizer.TT_EOF) {
                  while (streamTokenizer.ttype != '}') {
                      //For each item
                      //streamTokenizer.nextToken();
                      //while (streamTokenizer.ttype != '}'){
                      //System.out.print(streamTokenizer.nval+":");
                      numAttribute = (int) streamTokenizer.nval;
                      streamTokenizer.nextToken();
  
                      if (streamTokenizer.ttype == StreamTokenizer.TT_NUMBER) {
                          //System.out.print(streamTokenizer.nval + " ");
                          this.setValue(instance, numAttribute, streamTokenizer.nval, true);
                          //numAttribute++;
  
                      } else if (streamTokenizer.sval != null && (streamTokenizer.ttype == StreamTokenizer.TT_WORD
                              || streamTokenizer.ttype == 34)) {
                          //System.out.print(streamTokenizer.sval + "/"+this.instanceInformation.attribute(numAttribute).indexOfValue(streamTokenizer.sval)+" ");
                          if (this.auxAttributes.get(numAttribute).isNumeric()) {
                              this.setValue(instance, numAttribute, Double.valueOf(streamTokenizer.sval).doubleValue(), true);
                          } else {
                              this.setValue(instance, numAttribute, this.instanceInformation.attribute(numAttribute).indexOfValue(streamTokenizer.sval), false);
                              //numAttribute++;
                          }
                      }
                      streamTokenizer.nextToken();
                  }
                  streamTokenizer.nextToken(); //Remove the '}' char
              }
              streamTokenizer.nextToken();
              //System.out.println("EOL");
              //}
  
          } catch (IOException ex) {
              Logger.getLogger(ArffLoader.class.getName()).log(Level.SEVERE, null, ex);
          }
          return instance;
      }