#include <algorithm>
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using pii = pair<int, int>;
using vpii = vector<pii>;
using vi = vector<int>;
using vll = vector<long long>;
using mpii = map<int, int>;
using mpll = map<ll, ll>;
using db = long double;

#define pb push_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define lb lower_bound
#define ub upper_bound
#define make_unique(x)                                                         \
  sort(all((x)));                                                              \
  (x).resize(unique(all((x))) - (x).begin())
#define ceil(a, b) ((a) + (b)-1) / (b)

const int mod = (int)1e9 + 7;
const db pi = acos((db)-1);
const int dx[4]{1, 0, -1, 0};
const int dy[4]{0, 1, 0, -1};

#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 42
#endif

/* stuff you should look for:
  ---------------------------
   * special cases (n=1?)
   * int overflow, array bounds
   * do smth instead of nothing and stay organized
   * WRITE STUFF DOWN
   * DON'T GET STUCK ON ONE APPROACH
 */

ll findMaxSubarray(const vector<int> &nums) {
  if (nums.empty() || all_of(all(nums), [](int x) { return x < 0; }))
    return 0;

  ll maxSum = nums[0];
  ll currentSum = nums[0];

  for (int i = 1; i < nums.size(); i++) {
    if (currentSum < 0) {
      currentSum = nums[i];
    } else {
      currentSum += nums[i];
    }

    if (currentSum > maxSum) {
      maxSum = currentSum;
    }
  }

  return maxSum;
}

void solve() {
  int n, k;
  cin >> n >> k;
  vi v(n);
  ll sum = 0;
  for (auto &x : v) {
    cin >> x;
    sum += x;
  }
  ll maxSum = findMaxSubarray(v);
  ll res = 2;
  for (int i = 1; i < k; i++) {
    res = (2 * res) % mod;
  }
  res = ((res % mod) * (maxSum % mod) - maxSum) % mod;
  sum += res;
  if (sum % mod < 0) {
    cout << sum % mod + mod << '\n';
  } else {
    cout << sum % mod << '\n';
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tt;
  cin >> tt;
  while (tt--) {
    solve();
  }
}