#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;
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];
void get(){
	E.clear(),S.clear(),P.clear(),ans.clear();
	scanf("%d%d",&n,&m);
	iota(fa,fa+1+n,0);
	fill(deg+1,deg+1+n,0);
	for(int u,v;m--;){
		scanf("%d%d",&u,&v);
		P.push_back({u,v});
		if(!merge(u,v))E.push_back({u,v});
		else S.push_back({u,v}),deg[u]++,deg[v]++;
	}
	int rt=max_element(deg+1,deg+1+n)-deg;
	iota(fa,fa+1+n,0);
	for(auto e:S)if(e.first!=rt&&e.second!=rt){
		merge(e.first,e.second);
	}
	// debug(ary(fa,1,n));
	for(auto e:E)if(e.first!=rt&&e.second!=rt){
		if(deg[rt]*2<=n)break;
		// debug(e.first,e.second);
		if(merge(e.first,e.second))ans.push_back(e),deg[rt]--;
	}
	if(deg[rt]*2>n){
		puts("No");return;
	}
	iota(fa,fa+1+n,0);
	for(auto e:ans)merge(e.first,e.second);
	for(auto e:P)if(merge(e.first,e.second))ans.push_back(e);
	puts("Yes");
	for(auto e:ans)printf("%d %d\n",e.first,e.second);
}
int main(){
	for(scanf("%d",&T);T--;)get();
	return 0;
}