@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Ground other = (Ground) obj;
		if (!Arrays.deepEquals(grid, other.grid))
			return false;
		if (higherLeftPoint == null) {
			if (other.higherLeftPoint != null)
				return false;
		} else if (!higherLeftPoint.equals(other.higherLeftPoint))
			return false;
		return true;
	}