#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define int long long
#define double long double
#define pb push_back
#define mp make_pair
#define endl '\n'
#define all(x) x.begin(),x.end()
#define fill(a,b) memset(a,b,sizeof(a))
#define sz(x) (int)x.size()
#define ff first
#define ss second
#define lb lower_bound
#define ub upper_bound
#define bs binary_search
#define rep(i, begin, end) for (__typeof(end) i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))
#define deb(x) cout<<#x<<" "<<x<<endl;
#define T int t; cin>>t; while(t--)
#define fst ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

int firstMissingPositive(int arr[], int n)
{
     
    for (int i = 0; i < n; i++) {

        while (arr[i] >= 1 && arr[i] <= n
               && arr[i] != arr[arr[i] - 1]) {
            swap(arr[i], arr[arr[i] - 1]);
        }
    }

    for (int i = 0; i < n; i++) {
        if (arr[i] != i + 1) {
            return i + 1;
        }
    }
   
    return n + 1;
}

signed main()
{

    fst;

#ifndef ONLINE_JUDGE
    freopen("input3.txt", "r", stdin);
    freopen("output3.txt", "w", stdout);
#endif

    
    T{
        int n,p,q, m,h, k, sum = 0, cnt=0, x, y, z, flag = 0, pos, diff,r=0,l=0,u=0,d=0,cnt1=0,cnt0=0,cnt2=0,ans,mi=INT_MAX,mx=INT_MIN;
        cin>>n;
        
        int a[n];
        vector<int> v,v1,v2;
        set<int> st;
        map<int,int> mp;

        rep(i,0,n) {
            cin>>x;
            if(find(all(st),x) != st.end())
              v.pb(x);
            st.insert(x);
        }

        for(auto i:st) cout<<i<<" ";
        sort(all(v));

        for(auto i:v) cout<<i<<" ";


        cout<<endl;

        v.clear();
        st.clear();

    }
}
