// UUID: 30952f48-039f-4fe9-bab9-ad568dcdd2be
#include <bits/stdc++.h>
#include <vector>
using namespace std;


vector<vector<int>> feltetelek;
vector<bool> done;
vector<int> p;
bool err;
void melysegi(int v) {
	done[v] = true;
	for (int i:feltetelek[v]) {
		if (!done[i]) {
			if (p[v] == 0) p[i] = 1;
			else p[i] = 0;
			melysegi(i);
		}
		else if (p[i] == p[v]) {
			err = true;
		}
	}
}
int main() {
	int t;cin >> t;
	for (int T = 0;T < t;T++) {
		err = false;
		int n,k;cin >> n >> k;
		feltetelek.clear();
		done.clear();
		n++;
		feltetelek.resize(n);
		done.resize(n);
		p = vector<int>(n, -1);
		for (int i = 0;i < k;i++) {
			int a,b;cin >> a >> b;
			b++;
			feltetelek[a - 1].push_back(b - 1);
			feltetelek[b - 1].push_back(a - 1);
		}
		int c = 0;
		for (int i = 0;i < n;i++) {
			if (!done[i]) {
				c++;
				p[i] = 0;
				melysegi(i);
			}
		}
		if (err) cout << 0 << endl;
		else {
			int val = 1;
			for (int i = 1;i < c;i++) {
				val = (2 * val) % 1000000007;
			}
			cout << val << endl;
		}
	}
}