#include<bits/stdc++.h>
using namespace std;
const int N=3e5+5;
using ll=long long;
int T;
int n;
struct node{
	int a,b,id; 
}p[N],q[N];
struct ANS{
	int x,y,z;
}ans[N];
priority_queue<int>pq;
int to[N],tmp[N];
bool vis[N];
int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>T;
	while(T--){
		cin>>n;
		int m=3*n;
		for(int i=1;i<=m;i++){
			vis[i]=0;
			cin>>p[i].a>>p[i].b;p[i].id=i;
			q[i]=p[i];
		}
		sort(p+1,p+1+m,[&](const node A,const node B){
			return A.b==B.b?A.a<B.a:A.b<B.b; 
		});
		for(int i=1;i<=m;i++)to[p[i].id]=i;
		sort(q+1,q+1+m,[&](const node A,const node B){
			return A.a<B.a;
		});
		while(!pq.empty())pq.pop();
		int pos=1,tot=0;
		bool fl=1;
		for(int i=1;i<=m;i++){
			if(vis[p[i].id])continue;
			while(pos<=m&&q[pos].a<=p[i].b)pq.push(to[q[pos].id]),pos++;
			int cnt=1;tmp[1]=p[i].id;
			vis[p[i].id]=1;
			while(!pq.empty()){
				int u=pq.top();pq.pop();
				if(vis[p[u].id])continue;
				tmp[++cnt]=p[u].id;
				if(cnt==3)break;
			}
			if(cnt^3){
				fl=0;break;
			}
			++tot;
			ans[tot]={tmp[1],tmp[2],tmp[3]};
			for(int i=1;i<=3;i++)vis[tmp[i]]=1;
		}
		if(!fl){
			cout<<"No\n";continue;
		}
		cout<<"Yes\n";
		for(int i=1;i<=n;i++){
			cout<<ans[i].x<<" "<<ans[i].y<<" "<<ans[i].z<<"\n";
		}
	}
	return 0;
}