#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define rep(i, l, r) for(ll i = l; i < r; i++)
#define all(ar) begin(ar), end(ar)

void solve() {
    int N;
    cin >> N;
    int n = N * 3;
    vector<pair<ll, ll>> ab;
    vector<ll> z;
    rep(i, 0, n) {
        ll a, b;
        cin >> a >> b;
        ab.emplace_back(a, b);
        z.push_back(a);
        z.push_back(b);
    }

    sort(all(z));
    z.erase(unique(all(z)), z.end());

    for(auto &[a, b] : ab) {
        a = lower_bound(all(z), a) - z.begin();
        b = lower_bound(all(z), b) - z.begin();
    }

    sort(all(ab));
    vector<vector<int>> ib(z.size());
    rep(i, 0, n) ib[ab[i].second].push_back(i);

    priority_queue<ll> pq;
    vector<bool> used(n);
    int nxt = n - 1;
    int mn = z.size();
    vector<tuple<int, int, int>> ans;
    rep(i, 0, N) {
        while(used[nxt]) nxt--;
        int a = ab[nxt].first;
        used[nxt] = true;
        rep(j, a, mn) {
            for(int idx : ib[j]) {
                if(!used[idx]) pq.push(idx);
            }
        }
        mn = a;
        vector<int> tmp;
        rep(j, 0, 2) {
            if(pq.empty()) {
                cout << "No" << endl;
                return;
            }
            int t = pq.top();
            pq.pop();
            if(used[t]) {
                j--;
                continue;
            }
            used[t] = true;
            tmp.push_back(t);
        }
        ans.emplace_back(nxt, tmp[0], tmp[1]);
    }

    cout << "Yes" << endl;
    for(auto [a, b, c] : ans) {
        cout << a + 1 << " " << b + 1 << " " << c + 1 << endl;
    }
}

int main() {
    int t;
    cin >> t;
    while(t--) {
        solve();
    }
}