public boolean findTarget(TreeNode root, int k) {
        Map<Integer, Integer> map= new HashMap<>();
        go(map, root);
        for(Integer key : map.keySet()){
            int v=k-key;
            if(v!=key){
                if(map.containsKey(v))return true;
            }else{
                if(map.get(v)>1)return true;
            }
        }
        return false;
    }
Why Did you create this class? what does it do?
src/problems/easy/TwoSumIVInputisaBST.java