docs: public static void drawTree(Cluster a, Graphics2D g, int x, int y, int level) {  
  	    level++;  
  	    g.setPaint(Color.RED);
  	    g.drawString(a.getN(), x-wunit/2, y+hunit/2);  
  	    int newx = width/level/4;
  	    if (a.getLeft() != null) {  
  	    	g.setPaint(Color.BLACK);
  	        g.drawLine(x, y, x - newx , y + hunit);  
  	        drawTree(a.getLeft(), g, x - newx, y + hunit,  level);  
  	    }  
  	    if (a.getRight() != null) {  
  	    	g.setPaint(Color.BLACK);
  	        g.drawLine(x, y, x + newx, y + hunit);  
  	        drawTree(a.getRight(), g, x + newx, y +hunit, level);  
  	    }  
  	    
  	}