# UUID: f3d6e7a0-a56c-4e42-980c-1b3d69e537f1
from sys import stdin

def modpow(a, n, M):
    e = 1
    while n:
        if n % 2:
            e *= a
            e %= M
        n //= 2
        a *= a
        a %= M
    return e


def megold():
    N, K = (int(x) for x in input().split())
    elek = {0: []}
    for _ in range(K):
        a, b = stdin.readline().split()
        a = int(a) - 1; b = int(b)
        elek.setdefault(a, []).append(b)
        elek.setdefault(b, []).append(a)
    jart = dict((cs, 0) for cs in elek.keys())
    k = 0
    for cs in elek.keys():
        if jart[cs]:
            continue
        k += 1
        sor = [cs]
        jart[cs] = 1
        while sor:
            cs2 = sor.pop()
            j2 = jart[cs2]
            for cs3 in elek[cs2]:
                j3 = jart[cs3]
                if j3 == 0:
                    jart[cs3] = -j2
                    sor.append(cs3)
                elif j3 == j2:
                    return 0
    k += N - len(elek)
    return modpow(2, k, 10**9 + 7)


T = int(input())
for i in range(T):
    print(megold())