#include<cstdio>

#include<cstring>

#include<cmath>

#include<algorithm>

using namespace std;

const int maxn =  + ;

int tott[maxn];

int father[maxn];

int find(int x)

{

    if (x != father[x]) father[x] = find(father[x]);

    return father[x];

}

int main()

{

    int T;

    scanf("%d", &T);

    while (T--)

    {

        int i, n, m, u, v;

        scanf("%d%d", &n, &m);

        for (i = ; i <= n; i++) father[i] = i;

        memset(tott, , sizeof(tott));

        for (i = ; i < m; i++)

        {

            scanf("%d%d", &u, &v);

            int fu = find(u);

            int fv = find(v);

            if (fu != fv) father[fu] = fv;

            tott[u]++;

            tott[v]++;

        }

        int ji = , ou = ;

        for (i = ; i <= n; i++)

        {

            if (tott[i] == ) continue;

            if (tott[i] %  == ) ou++;

            else ji++;

        }

        int jieguo = ;

        int th = find();

        for (i = ; i <= n; i++)

        {

            int tg = find(i);

            if (tg != th) break;

        }

        if (i == n + ) jieguo = ;

        if (jieguo == )

        {

            if (ji ==  || ji == ) jieguo = ;

            else jieguo = ;

        }

        if (jieguo == ) printf("Yes\n");

        else printf("No\n");

    }

    return ;

}