return -1;
return null;
		private int search(long gid) {			int low = 0;			int high = length - 1;			int mid;			int cmp;			while (low <= high) {				mid = (low + high) / 2;				if (array[mid].gid == gid)					return mid;				if (array[mid].gid > gid)					high = mid - 1;				else					low = mid + 1;			}			return -1;		}