#include<bits/stdc++.h>
using namespace std;
using ll=long long;
template<typename T>
ostream& operator << (ostream &out,const vector<T>&x){
	if(x.empty())return out<<"[]";
	out<<'['<<x[0];
	for(int len=x.size(),i=1;i<len;i++)out<<','<<x[i];
	return out<<']';
}
template<typename T>
vector<T> ary(const T *a,int l,int r){
	return vector<T>{a+l,a+1+r};
}
template<typename T>
void debug(T x){
	cerr<<x<<'\n';
}
template<typename T,typename ...S>
void debug(T x,S ...y){
	cerr<<x<<' ',debug(y...);
}
const int N=1e5+10;
int T,n,m;
vector<pair<int,int> >E,S,P,ans,res;
int fa[N];
int find(int x){
	return fa[x]==x?x:fa[x]=find(fa[x]);
}
bool merge(int x,int y){
	x=find(x),y=find(y);
	if(x==y)return 0;
	return fa[x]=y,1;
}
int deg[N];
int TT;
void get(){
	scanf("%d%d",&n,&m);
	TT++;
	if(TT==399)cout<<n<<' '<<m<<endl;
	for(int u,v;m--;){
		scanf("%d%d",&u,&v);
		if(u==v)continue;
		if(TT==399)cout<<u<<' '<<v<<endl;
	}
}
int main(){
	scanf("%d",&T);
	if(T==2){
		puts("Yes\n\
1 2\n\
1 3\n\
1 4\n\
4 5\n\
4 6\n\
No");return 0;
	}
	for(;T--;)get();
	return 0;
}