#include <bits/stdc++.h>  
using namespace std;  

#define int long long  

using ull = unsigned long long;

const ull mask = mt19937_64(time(nullptr))();

ull shift(ull x) {
 	x ^= mask;
 	x ^= x << 13;
  	x ^= x >> 7;
  	x ^= x << 17;
  	x ^= mask;
  	return x;
}

void solve() {
	int n, m;
	cin >> n >> m;

	vector<pair<int, int>> e(m);
	for (auto &[x, y] : e) {
		cin >> x >> y;
	}

	if (n == m + 1 || n <= 4) {
		cout << "YES\n";
		return;
	}

	if (n < m) {
		cout << "NO\n";
		return;
	}

	vector<vector<int>> adj(n + 1);
	vector<int> deg(n + 1);
	for (auto [x, y] : e) {
		adj[x].push_back(y);
		adj[y].push_back(x);
		deg[x]++, deg[y]++;
	}

	vector<bool> cir(n + 1, true);
	queue<int> q;
	for (int i = 1; i <= n; i++) {
		if (deg[i] == 1) {
			cir[i] = false;
			q.push(i);
		}
	}

	while (!q.empty()) {
		int x = q.front();
		q.pop();
		for (auto y : adj[x]) {
			if (!cir[y]) {
				continue;
			}
			deg[y]--;
			if (deg[y] < 2) {
				cir[y] = false;
				q.push(y);
			}
		}
	}

	vector<vector<int>> a(n + 1);
	vector<vector<int>> b(n + 1);
	
	for (auto [x, y] : e) {
		if (cir[x] && cir[y]) {
			b[x].push_back(y), b[y].push_back(x);
			continue;
		}
		a[x].push_back(y), a[y].push_back(x);
	}

	vector<int> rt;
	vector<int> vis(n + 1);
	function<void(int, int)> dfs = [&](int x, int f) {
		vis[x] = true;
		rt.push_back(x);
		for (int y : b[x]) {
			if (y == f || vis[y]) {
				continue;
			}
			dfs(y, x);
		}
	};

	for (int i = 1; i <= n; i++) {
		if (cir[i]) {
			dfs(i, 0);
			break;
		}
	}

	function<ull(int, int)> get = [&](int x, int f) {
		ull ret = 1;
		for (auto y : a[x]) {
			if (y == f) {
				continue;
			}
			ret += shift(get(y, x));
		}
		return ret;
	};

	int sz = rt.size();
	vector<ull> hash(sz);
	for (int i = 0; i < sz; i++) {
		hash[i] = get(rt[i], 0);
	}

	if (hash == vector<ull>(sz, hash[0])) {
		cout << "YES\n";
		return;
	}

	if (sz % 2 == 0) {
		bool ok = true;
		for (int i = 2; i < sz; i++) {
			if (hash[i] != hash[i - 2]) {
				ok = false;
			}
		}
		cout << (ok ? "YES" : "NO") << "\n";
		return;
	}

	cout << "NO\n";
}

signed main() {  
    ios::sync_with_stdio(false);
    cin.tie(nullptr);  

    int t;
    cin >> t;
    while (t--) {
    	solve();
    }

    return 0;
}