#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb push_back
#define mp make_pair
#define ss second
#define ff first
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    #ifndef ONLINE_JUDGE
        freopen("input.txt","r",stdin);
        freopen("output.txt","w",stdout);
    #endif
    ll t;
    cin>>t;
    while(t--)
    {
        ll n;
        cin>>n;
        ll arr[2*n+1];
        map<ll,ll>hash;
        for(ll i=0;i<2*n;i++)
        {
        cin>>arr[i];
        hash[arr[i]]++;
        }
        sort(arr,arr+2*n);
        int flag2=0;
        for(ll i=0;i<2*n-1;i++)
        {
            ll x1=arr[i]+arr[2*n-1];
            ll x2=x1;
            //cout<<x1<<endl;
            multiset<ll>s;
            for(ll j=0;j<2*n;j++)
            s.insert(arr[j]);
            int flag1=0;
            vector<pair<ll,ll> >p1;
            for(ll j=0;j<n;j++)
            {
                multiset<ll>::iterator it,it1;
                it=s.end();
                it--;
                ll val=x1-*it;
                s.erase(it);
                it1=s.find(val);
                if(it1==s.end())
                {
                    flag1=1;
                    break;
                }
                else
                {
                     p1.pb(mp(x1-val,val));
                     x1=max(x1-val,val);
                     //cout<<x1<<" "<<val<<endl;
                    s.erase(it1);
                }
                
            }
            if(flag1==1)
            continue;
            else
            {
                cout<<"YES"<<endl;
                cout<<x2<<endl;
                flag2=1;
                for(ll j=0;j<p1.size();j++)
                cout<<p1[j].ff<<" "<<p1[j].ss<<endl;
                break;

            }
            
        }
        if(flag2==0)
        cout<<"NO"<<endl;
    }
    return 0;
}