docs: private void mergeClusters (int smallClus, int bigClus)
  	{		
  		//System.out.println("Merge clusters "+smallClus+" and "+bigClus+".");
  		// Iterate through the density grids in grid_list to find those which are in highClass
  		for (Map.Entry<DensityGrid, CharacteristicVector> grid : grid_list.entrySet())
  		{
  			DensityGrid dg = grid.getKey();
  			CharacteristicVector cv = grid.getValue();
  
  			// Assign density grids in smallClus to bigClus
  			if(cv.getLabel() == smallClus)
  			{
  				cv.setLabel(bigClus);
  				this.grid_list.put(dg, cv);
  			}
  		}
  		//System.out.println("Density grids assigned to cluster "+bigClus+".");
  		
  		// Merge the GridCluster objects representing each cluster
  		GridCluster bGC = this.cluster_list.get(bigClus);
  		bGC.absorbCluster(this.cluster_list.get(smallClus));
  		this.cluster_list.set(bigClus, bGC);
  		this.cluster_list.remove(smallClus);
  		//System.out.println("Cluster "+smallClus+" removed from list.");
  		cleanClusters();
  	}