#include <bits/stdc++.h>
using namespace std;

int main()
{
    long long int t = 0;
    cin >> t;
    long long int j = 0;
    while (j++ < t)
    {
        long long int inn;
        cin >> inn;
        long long int n = 2 * inn;
        long long int arr[n];
        for (long long int i = 0; i < n; i++)
        {
            cin >> arr[i];
        }

        long long int i = 1;
        long long int count = n;
        while (count > 0)
        {
            if (i == 0)
            {
                if ((arr[n - 1] + arr[i + 1]) / 2 == arr[i])
                {
                    long long int t = arr[n - 1];
                    arr[n - 1] = arr[i];
                    arr[i] = t;
                    count = n;
                    i++;
                    continue;
                }
                else
                {
                    i++;
                    count--;
                    continue;
                }
            }
            if (i == n - 1)
            {
                if ((arr[i - 1] + arr[0]) / 2 == arr[i])
                {
                    long long int t = arr[i - 1];
                    arr[i - 1] = arr[i];
                    arr[i] = t;
                    i = 0;
                    count = n;
                    continue;
                }
                else
                {
                    i = 0;
                    count--;
                    continue;
                }
            }
            else
            {
                if ((arr[i - 1] + arr[i + 1]) / 2 == arr[i])
                {
                    long long int t = arr[i - 1];
                    arr[i - 1] = arr[i];
                    arr[i] = t;
                    count = n;
                    i++;
                    continue;
                }
                else
                {
                    count--;
                    i++;
                    continue;
                }
            }
        }

        for (long long int i = 0; i < n; i++)
        {
            cout << arr[i] << " ";
        }
        cout << "\n";
    }

    return 0;
}