Leetcode 278. First Bad Version

public class Solution extends VersionControl {    public int firstBadVersion(int n) {        int low = 1, high = n, mid = 0;        while (low + 1 < high) {            mid = low + (high - low) / 2;            if (isBadVersion(mid))                 high = mid;            else                low = mid;        }        // result is among low and high        if (isBadVersion(low)) return low;        return high;    }}