#include<bits/stdc++.h>
using namespace std;
#define rep(i,x,y) for (int i=(x);i<=(y);i++)
#define drep(i,y,x) for (int i=(y);i>=(x);i--)
#define pii pair<int,int>
#define fir first
#define sec second
#define MP make_pair
#define templ template<typename T>
templ bool chkmin(T &x,T y){return x>y?x=y,1:0;}
templ bool chkmax(T &x,T y){return x<y?x=y,1:0;}
void file() {
    #ifdef zqj
    freopen("a.in","r",stdin);
    #endif
}
typedef long long ll;
#define sz 201010

int n,m;
int deg[sz],cc[sz];

void work() {
    cin>>n>>m;
    set<pii>E;
    int x,y;
    rep(i,1,m) cin>>x>>y,E.insert(minmax(x,y));
    if (n<=6) {
        static int p[sz];
        rep(i,1,n) p[i]=i;
        int cnt=0;
        do {
            set<pii>ee;
            for (auto [x,y]:E) ee.insert(minmax(p[x],p[y]));
            if (ee==E) ++cnt;
        } while (next_permutation(p+1,p+n+1));
        int fac=1; rep(i,1,n) fac*=i;
        cnt=fac/cnt;
        cout<<(cnt<=n?"YES":"NO")<<'\n';
        return; 
    }
    rep(i,0,n) deg[i]=cc[i]=0;
    for (auto [x,y]:E) ++deg[x],++deg[y];
    rep(i,1,n) ++cc[deg[i]];
    rep(i,2,n-3) if (cc[i]) {
        cout<<"NO\n";
        return;
    }
    if (cc[n-1]) swap(cc[n-1],cc[0]),swap(cc[n-2],cc[1]);
    if (cc[0]) {
        if (!cc[1]) cout<<"YES\n";
        else cout<<"NO\n";
        return;
    }
    assert(cc[1]==n||cc[n-2]==n);
    cout<<"NO\n";
}

int main() {
    file();
    ios::sync_with_stdio(false),cin.tie(0);
    int T; cin>>T;
    while (T--) work();
    return 0;
}