import sys
from collections import defaultdict
input=sys.stdin.readline
write=sys.stdout.write\

T=int(input())
X=[0]*T
for case in range(T):
    N,M=map(int,input().split())
    deg=[0]*(N+1); deg[0]=-1

    for _ in range(M):
        u,v=map(int,input().split())
        deg[u]+=1
        deg[v]+=1

    C=defaultdict(int)
    for v in range(1,N+1):
        C[deg[v]]+=1

    if max(C.values())>=2:
        X[case]=1

write("\n".join(map(lambda x:"Yes" if x else "No",X)))