public boolean equals(MapData md) {
		if (md.data.size() != this.data.size())
			return false;
		for (Tile t : md.data.keySet()) {
			if (!this.data.containsKey(t) || !Arrays.equals(md.data.get(t), this.data.get(t)))
				return false;
		}
		return true;
	}