#include <bits/stdc++.h>
using namespace std;
const int N = 110;
const long long mod = 1e9 + 7LL;
vector<int> lista[N];
int vis[N], g[N], peso[N], qt;
long long dp[N][N], visdp[N][N], t = 0;
long long solve(int pos, int k) {
  if (!k) return 1;
  if (pos == qt) return 0;
  long long &ans = dp[pos][k];
  if (visdp[pos][k] == t) return ans;
  visdp[pos][k] = t;
  ans = (peso[pos] * solve(pos + 1, k - 1) + solve(pos + 1, k)) % mod;
  return ans;
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n, c;
  int q;
  cin >> q;
  while (q--) {
    cin >> n >> c;
    for (int i = 0; i <= n; ++i) {
      vis[i] = 0;
      lista[i].clear();
    }
    for (int i = 0; i < n - 1; ++i) {
      int a, b;
      cin >> a >> b;
      lista[a].push_back(b);
      lista[b].push_back(a);
    }
    long long ans = 0;
    if (c == 2) {
      cout << n * (n - 1) / 2 << "\n";
      continue;
    }
    for (int i = 1; i <= n; ++i) {
      queue<int> f, f1;
      vis[i] = i;
      qt = 0;
      for (int u : lista[i]) {
        g[u] = qt++;
        peso[g[u]] = 1;
        vis[u] = i;
        f.push(u);
      }
      t++;
      ans = (ans + solve(0, c)) % mod;
      while (!f.empty()) {
        while (!f.empty()) {
          int u = f.front();
          f.pop();
          peso[g[u]]--;
          for (int v : lista[u])
            if (vis[v] != i) {
              g[v] = g[u];
              peso[g[v]]++;
              vis[v] = i;
              f1.push(v);
            }
        }
        t++;
        ans = (ans + solve(0, c)) % mod;
        swap(f1, f);
      }
    }
    cout << ans << "\n";
  }
  return 0;
}
