#include<iostream>
#include<cstring>
#include<vector>
#include<set>
#include<numeric>
#include<algorithm>
using namespace std;
using LL = long long;

int main(){

#ifdef LOCAL
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif

    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);

    int T;
    cin >> T;
    while(T--){
        int n, m;
        cin >> n >> m;
        vector<pair<int, int> > edge(m);
        for(int i = 0; i < m; i++){
            int a, b;
            cin >> a >> b;
            a--, b--;
            if (a > b) swap(a, b);
            edge[i] = {a, b};
        }
        if (1LL * n * (n - 1) / 2 == m or m == 0){
            cout << "YES" << '\n';
            continue;
        }
        if (n > 5){
            vector<int> d(n);
            for(auto [x, y] : edge){
                d[x] += 1;
                d[y] += 1;
            }
            if (m == 1LL * (n - 1) * (n - 2) / 2){
                int t = 0;
                while(t < n and d[t] != 0) t++;
                cout << (t == n ? "NO" : "YES") << '\n';
            }
            else if (m == n - 1){
                int t = 1;
                while(t < n and d[t] != n - 1) t++;
                cout << (t == n ? "NO" : "YES") << '\n';
            }
            else{
                cout << "NO" << '\n';
            }
            continue;
        }
        vector<int> id(n);
        iota(id.begin(), id.end(), 0);
        set<vector<pair<int, int> > > s;
        do{
            auto nedge = edge;
            for(auto &[x, y] : nedge){
                x = id[x];
                y = id[y];
                if (x > y) swap(x, y);
            }
            sort(nedge.begin(), nedge.end());
            s.insert(nedge);
        }while(next_permutation(id.begin(), id.end()));
        cout << (s.size() <= n ? "YES" : "NO") << '\n';
    }

}