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

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());    //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long; 
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>; 

long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (300006)
ll t, n, m, C[MAXN];
vector<int> v[MAXN];

void solve() {
	cin>>n>>m;
	FOR(i,1,m){
		ll a,b;
		cin>>a>>b;
		v[a].eb(b), v[b].eb(a);
	}
	function<void(ll,ll)>dfs=[&](ll x,ll b){
		C[x] = b;
		bool lol = 0;
		for(auto i:v[x]) if(C[i] == C[x]) lol = 1;
		if(lol && b) {
			C[x] = 0;
			for(auto i:v[x]) if(C[i] == -1) dfs(i, 1);
		} else {
			for(auto i:v[x]) if(C[i] == -1) {
				dfs(i, !b);
			}
		}
	};
	dfs(1, 1);
	bool gg = 0;
	ll cnt = 0;
	FOR(i,1,n) if(C[i] == -1) {
		gg = 1;
	} else cnt += C[i];
	if(gg) cout<<"NO\n";
	else {
		cout<<"YES\n";
		cout<<cnt<<'\n';
		FOR(i,1,n) if(C[i]) cout<<i<<' ';
		cout<<'\n';
	}
	FOR(i,1,n) C[i]=-1, v[i].clear();
}
int main() {
	FAST
	mmst(C, -1);
	cin>>t;
	while(t--){
		solve();
	}
}
