public void place(MuseumObject o) {
		Space s = grid[o.getPosX()][o.getPosY()];
		if (o instanceof Intruder) {
			placeIntruder((Intruder) o);
		
		} else if (o instanceof Entrance) {
			placeEntrance((Entrance) o);
		} else if (s.isEmpty()) {
			s.setObject(o);
			if (o instanceof Sensor) {
				((Sensor) o).setMonitoredZone(grid);
			}
			
		} else {
			System.out.println("Space is not free Object: ");
		}
		
	}