// what is matter? never mind. 
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,sse4,popcnt,abm,mmx,avx,avx2") 
#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
//#define int long long
//#define ull unsigned long long
#define SZ(x) ((int)((x).size()))
#define ALL(x) (x).begin(),(x).end()
using namespace std;
inline int read()
{
    char c=getchar();int x=0;bool f=0;
    for(;!isdigit(c);c=getchar())f^=!(c^45);
    for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
    if(f)x=-x;return x;
}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;

#define maxn 2000006
#define inf 0x3f3f3f3f

int n,m;
vi e[maxn],g[maxn];
int cnt;
int fa[maxn],dfn[maxn],low[maxn],bel[maxn],idx;
int stk[maxn],tp;

int ff[maxn*2];
int gf(int x){
	while(x!=ff[x])x=ff[x]=ff[ff[x]];
	return x;
}
void mg(int x,int y){
	ff[gf(x)]=gf(y);
}
int deg[maxn],vis[maxn];

int tim,ts[maxn];

struct ttmp{
	vi o; 
	int n;
	vector<pii>E;
	void init1(vi t,int u){
		o=t; o.pb(u);
		n=o.size();
		E.clear();
	}
	void adde(int u,int v){
		if(!n)return;
		if(u<v)
			E.pb(mkp(u,v));
	}
	bool isok(){
//		cout<<"chk\n";
++tim;
		for(int x:o) ff[x]=x,ff[x+::n]=x+::n,deg[x]=0,ts[x]=tim;
		for(auto [u,v]:E){
			mg(u,v+::n);
			mg(v,u+::n);
			++deg[u],++deg[v];
//			cout<<"u,v "<<u<<" "<<v<<"\n";
		}
		for(int x:o) if(gf(x)==gf(x+::n)) return 0;
		
		if(n<=2) return 1;
		
		auto Have=[&](int u){
			int hav=0;
			for(int v:e[u]) if(ts[v]!=tim && e[v].size()>1) return 1;
			return 0; 
		};
		
		if(n==4 && E.size()==4) {
			int cc=0;
			For(i,0,SZ(o)-1){
				if(deg[o[i]]!=2) return 0;
				cc+=(deg[o[i]]<::e[o[i]].size());
				if(cc>=4) return 0;
			}
			For(i,0,SZ(o)-1)
				if(Have(o[i]) && Have(o[(i+1)%4])) return 0;
			int cc2=0;
			For(i,0,SZ(o)-1) cc2+=Have(o[i]);
			if(cc>=3 && cc2>=2) return 0;
			return 1;
		}
		
		int cc2=0;
		for(int u:o){
			cc2+=Have(u);
		}
		
		sort(ALL(o),[&](int x,int y){
			return deg[x]>deg[y];
		});
		int cct2=Have(o[0]) + Have(o[1]);
		
///		cout<<"c2: "<<cc2<<" "<<cct2<<"\n";
		
		if(cc2>=3) return 0;
		if(cc2>=2 && cct2<2) return 0;
		
		int cc1=0,cct1=0;
		For(i,0,(int)SZ(o)-1){
			if(i>=2 && deg[o[i]]!=2) return 0;
			if(i>=2) cc1+=(deg[o[i]]<::e[o[i]].size());
			else cct1+=(deg[o[i]]<::e[o[i]].size());
		}
		
		
		if(cc1>=2) return 0;
		if(cc2>=2 && cc1+cct1>=3) return 0;
		
		int x=o[0],y=o[1];
//		cout<<"x,y "<<x<<" "<<y<<"\n";
		for(auto [u,v]:E){
			if((u!=x&&u!=y)&&(v!=x&&v!=y)) return 0;
		}
		return 1;
	}
}t[maxn];

void tar(int u,int pa)
{
	dfn[u]=low[u]=++idx,stk[++tp]=u;
	for(auto v:e[u]){
		if(v==pa)continue;
		if(!dfn[v]){
			tar(v,u);
			low[u]=min(low[u],low[v]);
			if(low[v]>=dfn[u]){
				++cnt; int x; 
				g[u].pb(cnt); fa[cnt]=u;// cout<<"addg "<<u<<' '<<cnt<<endl;
				fa[cnt]=u;
				do{
					x=stk[tp--];
					g[cnt].pb(x),bel[x]=cnt; //cout<<"addg "<<cnt<<" "<<x<<endl;
					fa[x]=cnt;
				}while(x!=v);
			}
		}
		else low[u]=min(low[u],dfn[v]);
	}
}

bool work(int ID)
{
	//cout<<ID<<" ";
	n=read(),m=read();
	For(i,1,n*2) e[i].clear(),dfn[i]=low[i]=bel[i]=fa[i]=0,g[i].clear(); idx=0;
	For(i,1,m){
		int u=read(),v=read();
		e[u].pb(v),e[v].pb(u);
	}
	cnt=n; tar(1,0);
	//cout<<"cnt "<<cnt<<"\n";
	For(i,n+1,cnt) t[i].init1(g[i],fa[i]);
	For(u,1,n)
		for(auto v:e[u]){
			if(fa[v]==fa[u]) t[fa[u]].adde(u,v);
			if(fa[fa[v]]==u) t[fa[v]].adde(u,v);
			if(fa[fa[u]]==v) t[fa[u]].adde(u,v);
		}
	//puts("QWQ");
	For(i,n+1,cnt) if(!t[i].isok()) return 0;
    return 1;
}

signed main()
{
	//freopen("data.in","r",stdin);
	//freopen("my.out","w",stdout);
	int T=read();
	For(_,1,T){
		if(work(_))puts("YES");
		else puts("NO");
	}
	return 0;
}
/*
3
3 3 1 2 2 3 3 1 4 4 1 2 2 3 3 4 4 1 6 6 1 2 2 3 3 4 4 5 5 6 6 1
3
6 5 1 2 2 3 2 4 2 5 5 6 4 6 1 2 1 3 1 4 2 3 2 4 3 4 5 6 1 2 1 3 1 4 2 5 3 5 4 5
00 00
11 00


*/