#include <bits/stdc++.h>
using namespace std;
#define maxn 10010
const int N = 5e4 + 10;
inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9')
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
    {
        x = (x << 1) + (x << 3) + (ch ^ 48);
        ch = getchar();
    }
    return x * f;
}
inline void write(int x)
{
    if (x < 0)
        putchar('-'), x = -x;
    if (x > 9)
        write(x / 10);
    putchar(x % 10 + '0');
    return;
}
int T, n;
int a[N], uniquer[N];
int main()
{
    T = read();
    while (T--)
    {
        n = read();
        for (int i = 1; i <= n; i++)
        {
            a[i] = read();
        }
        write(a[1]);
        putchar(' ');
        for (int i = 2; i <= n; i++)
        {
            for (int j = i; j <= i; j++)
            {
                if (a[j] == uniquer[j])
                {
                    break;
                }
            }
        }
        for (int i = 2; i <= n; i++)
        {
            if (uniquer[i] != 0)
            {
                write(uniquer[i]);
                putchar(' ');
            }
        }
    }
    return 0;
}