#include<random>
#include<iostream>
#include<iomanip>
#include<ctime>
#include<cmath>
#include<cctype>
#include<cstdio>
#include<cstdlib>
#include<climits>
// #define NDEBUG
#include<cassert>
#include<cstring>
#include<complex>
#include<algorithm>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<bitset>
#include<vector>
// #define LL __int128
#define LL long long
#define ULL unsigned LL
#define uint unsigned int
// #define int LL
// #define double long double
#define mkp make_pair
#define par pair<int,int>
#define epb emplace_back
#define psb push_back
#define f(x) ((x).first)
#define s(x) ((x).second)
using namespace std;
#define Lbt(x) ((x)&(-(x)))
#define Swap(x,y) (x^=y^=x^=y)
const int Mxxx=1e5;
inline char gc()
{
    // return getchar();
    static char buf[Mxxx],*p1=buf,*p2=buf;
    return (p1==p2&&(p2=(p1=buf)+fread(buf,1,Mxxx,stdin),p1==p2))?EOF:*p1++;
}
inline char pc(char ch,bool fl=false)
{
    // return fl?0:putchar(ch),0;
    static char buf[Mxxx],*p1=buf,*p2=buf+Mxxx;
    return (fl||((*p1++=ch)&&p1==p2))&&(fwrite(buf,1,p1-buf,stdout),p1=buf),0;
}
#define output pc('!',true)
inline int read()
{
    char ch=gc();
    int gans=0,gflag=0;
    for(;ch<'0'||'9'<ch;ch=gc())gflag|=(ch=='-');
    for(;'0'<=ch&&ch<='9';ch=gc())gans=(gans<<1)+(gans<<3)+(ch^48);
    return gflag?-gans:gans;
}
template<typename T>
inline char read(T&gans)
{
    char ch=gc();
    int gflag=0;gans=0;
    for(;ch<'0'||'9'<ch;ch=gc())gflag|=(ch=='-');
    for(;'0'<=ch&&ch<='9';ch=gc())gans=(gans<<1)+(gans<<3)+(ch^48);
    return gans=gflag?-gans:gans,ch;
}
template<typename T>
inline void write(T x)
{
    if(x>9)write(x/10);
    pc(x%10^48);
}
template<typename T>
inline void writenum(T x,char ch)
{
    if(x<0)x=-x,pc('-');
    write(x),pc(ch);
}
inline void writechar(char x,char ch)
{
    pc(x),pc(ch);
}
template<typename T>
inline T Max(T x,T y)
{
    return x>y?x:y;
}
template<typename T>
inline T Min(T x,T y)
{
    return x<y?x:y;
}
template<typename T>
inline T Abs(T x)
{
    return x<0?-x:x;
}
template<typename T>
inline void ckmx(T&x,T y)
{
    x=Max(x,y);
}
template<typename T>
inline void ckmn(T&x,T y)
{
    x=Min(x,y);
}
const int Mx=1e5;
int TT,n,m,cnt,h[Mx+5],nxt[(Mx<<1)+5],tto[(Mx<<1)+5];
inline void ade(int x,int y)
{
    nxt[++cnt]=h[x];
    tto[h[x]=cnt]=y;
}
inline void Ade(int x,int y)
{
    ade(x,y);ade(y,x);
}
int onc[Mx+5],vs[Mx+5];
int top,stk[Mx+5];
inline int DFS(int x,int y)
{
    int i,to;
    assert(!vs[x]);
    vs[x]=1;
    for(i=h[x];i;i=nxt[i])if((to=tto[i])^y)
    {
        if(vs[to])return stk[++top]=x,onc[x]=1,to;
        int k=DFS(to,x);
        if(k)return stk[++top]=x,onc[x]=1,x==k?0:k;
    }
    return 0;
}
const int M=2e6;
int tot,pri[M+5],vst[M+5];
ULL F[Mx+5];int sz[Mx+5];
inline void Slv(int x,int y)
{
    int i,to;
    F[x]=sz[x]=1;
    for(i=h[x];i;i=nxt[i])if((to=tto[i])^x&&!onc[to])
    {
        Slv(to,x);
        F[x]+=F[to]*pri[sz[to]+5];
        sz[x]+=sz[to];
    }
}
signed main()
{
    #ifndef ONLINE_JUDGE
    freopen("_.in","r",stdin);
    // freopen("_.out","w",stdout);
    #endif
    int i,j,f;
    for(i=2;i<=M;i++)
    {
        if(!vst[i])vst[i]=pri[++tot]=i;
        for(j=1;j<=tot;j++)
        {
            if(pri[j]*i>M)break;
            vst[pri[j]*i]=pri[j];
            if(pri[j]==vst[i])break;
        }
    }
    for(TT=read();TT;TT--)
    {
        n=read();m=read();
        // cout<<"???\n";
        if(m==n-1){for(i=1;i<=m;i++)read(),read();puts("YES");continue;}
        if(m>n){for(i=1;i<=m;i++)read(),read();puts("NO");continue;}
        assert(m==n);
        cnt=0;for(i=1;i<=n;i++)h[i]=onc[i]=vs[i]=0;
        for(i=1;i<=m;i++)Ade(read(),read());
        top=0;assert(!DFS(1,0));
        for(i=1;i<=top;i++)Slv(stk[i],0);
        assert(top>=3);
        // cout<<"HERE! Ck:"<<top<<"\n";
        f=1;for(i=1;i<top;i++)f&=F[stk[i]]==F[stk[i+1]];
        if(f){puts("YES");continue;}
        f=!(top&1);for(i=1;i<=top-2;i++)f&=F[stk[i]]==F[stk[i+2]];
        for(i=2;i<=top-2;i++)f&=F[stk[i]]==F[stk[i+2]];
        if(f){puts("YES");continue;}
        puts("NO");
    }
    return output;
}
/*

*/