#include <bits/stdc++.h>
static char buf[1000000],*paa=buf,*pd=buf;
static char buf2[1000000],*pp=buf2;
#define getchar() paa==pd&&(pd=(paa=buf)+fread(buf,1,1000000,stdin),paa==pd)?EOF:*paa++
inline void pc(char ch){
	if(pp-buf2==1000000) fwrite(buf2,1,1000000,stdout),pp=buf2;
	*pp++=ch;
}
inline void pcc(){
	fwrite(buf2,1,pp-buf2,stdout);
	pp=buf2;
}
inline int read(void){
	int w=1;
	register int x(0);register char c(getchar());
	while(c<'0'||c>'9'){if(c=='-') w=-1;c=getchar();}
	while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return w*x;
}
void write(int x){
	static int sta[20];
	int top=0;
	do{
		sta[top++]=x%10,x/=10;
	}while(x);
	while(top) pc(sta[--top]+48);
}
void we(int x){
	write(x);
	pc('\n');
}
int T,N,M,ans[100009],dg[100009],pa[100009],id;
struct n_t{
	int a,b;
};
std::vector<int> as[100009];
inline int fr(int x) {
	while(x!=pa[x]) x=pa[x]=pa[pa[x]];
	return x;
}
inline void co(int x,int y) {
	x=fr(x),y=fr(y);
	if(x!=y) pa[x]=y;
}
bool cmp1(int m,int n) {
	return fr(m)<fr(n);
}
bool cmp2(n_t m,n_t n) {
	return fr(m.a)<fr(n.a);
}
bool sv(std::vector<int> x,std::vector<n_t> y) {
	if(x.size()==1) {
		ans[++id]=x[0];
		as[id].clear();
		return 1;
	}
	for(int i=0;i<x.size();i++) {
	//	printf("%d ",x[i]);
		dg[x[i]]=0;
		pa[x[i]]=x[i];
	}
	for(int i=0;i<y.size();i++) {
	//	printf("| %d %d",y[i].a,y[i].b);
		dg[y[i].a]++;
		dg[y[i].b]++;
	}
//	printf("\n");
	int pt=0;
	for(int i=0;i<x.size();i++) {
		if(dg[x[i]]==x.size()-1) {
			pt=x[i];
			break;
		}
	}
	if(pt==0) {
		return 0;
	}
	ans[++id]=pt;as[id].clear();
	std::vector<n_t> yy;
	std::vector<int> xx,rt,rt2;
	for(int i=0;i<y.size();i++) {
		if(y[i].a==pt||y[i].b==pt) continue;
		yy.push_back(y[i]);
		co(y[i].a,y[i].b);
	}
	y=yy;
	for(int i=0;i<x.size();i++) {
		if(x[i]!=pt) xx.push_back(x[i]);
	}
	x=xx;
	std::sort(y.begin(),y.end(),cmp2);
	std::sort(x.begin(),x.end(),cmp1);
	int i1=0,i2=0;
	int cur=id;
	for(int i=0;i<x.size();i++) {
		rt.push_back(fr(x[i]));
	}
	for(int i=0;i<y.size();i++) {
		rt2.push_back(fr(y[i].a));
	}
	for(int i=0;i<x.size();i++) {
		if(rt[i]!=x[i]) continue;
		int st=i1;
		while(i1<x.size()&&rt[i1]<=x[i]) {
			i1++;
		}
		int ed=i1-1;
		std::vector<int> xa;
		std::vector<n_t> ya;
		for(int j=st;j<=ed;j++) xa.push_back(x[j]);
		st=i2;
		while(i2<y.size()&&rt2[i2]<=x[i]) {
			if(rt2[i2]<x[i]) st=i2+1;
			i2++;
		}
		ed=i2-1;
		for(int j=st;j<=ed;j++) ya.push_back(y[j]);
		as[cur].push_back(x[i]);
		if(!sv(xa,ya)) return 0;
	}
	return 1;
}
signed main(void) {
	T=read();
	while(T--) {
		N=read();M=read();
		std::vector<int> x;
		std::vector<n_t> y;
		x.push_back(N+1);
		for(int i=1;i<=N;i++) x.push_back(i),y.push_back((n_t){i,N+1});
		for(int i=1;i<=M;i++) {
			int a=read(),b=read();
			y.push_back((n_t){a,b});
		}
		id=0;
		if(!sv(x,y)) {
			pc('N');pc('o');pc('\n');
			continue;
		}
		pc('Y');pc('e');pc('s');pc('\n');
		for(int i=id;i>=2;i--) {
			write(ans[i]),pc(' ');
			write(as[i].size()),pc(' ');
			for(int j=0;j<as[i].size();j++) write(as[i][j]),pc(' ');
			pc('\n');
		}
	}
	pcc();
}