code: private IntervalCategoryDataset createDataset() {
  		TaskSeries ts = null;
  		TaskSeriesCollection collection = new TaskSeriesCollection();
  		if ( solver.getVariables().length == 0) {
  			return collection;
  		}
  
  		ts = new TaskSeries("All");
  
  		for (int i = 0; i < solver.getVariables().length ; i++) {
  						
  			String label = solver.getVariables()[i].getComponent(); //dn.getNodes().elementAt(i).getLabel();
  			
  			if ( this.selectedVariables == null || this.selectedVariables.contains( label ) ) {
  			
  				SymbolicTimeline tl1 = new SymbolicTimeline(solver,label);
  	
  				for (int j = 0 ; j < tl1.getPulses().length-1 ; j++  ) {
  					
  					if ( tl1.getValues()[j] != null ) {
  						long startTime = tl1.getPulses()[j].longValue();
  						long endTime =   startTime + tl1.getDurations()[j].longValue();					
  						
  						Date startTask = new Date(startTime);
  						Date endTask = new Date(endTime);
  						Task task;
  						
  						String value = tl1.getValues()[j].toString().replace("[", "").replace("]", "");
  						if ( value.equals("true") )
  							task = new Task(label, startTask, endTask);
  						else
  							task = new Task(label + " := " + value, startTask, endTask);
  								
  					
  						ts.add(task);	
  					}
  				}
  			}
  		}
  		
  		collection.add(ts);
  
  		return collection;
  	}
docs: Creates a sample data set for a Gantt chart.
  
  @return The data set.