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



int main() {
  int t;cin>>t;
  while(t--){
	int n;cin>>n;
	vector<int> v(2*n);
	for(int i=0;i<2*n;i++){
		cin>>v[i];
	}
	//sort(v.begin(),v.end());
	while(true){
		int count = 0;
		for(int i=0;i<2*n;i++){
			int left = i -1;
			if(i == 0 )left= (2*n)-1;
			int right = i+1;
			if(i==(2*n)-1) right = 0;
			
			if(v[right]-v[i]== v[i]-v[left]){
				swap(v[i],v[left]);
				count++;
			}
		}
		//cout<<"count"<<count<<endl;
		if(count == 0)break;
	}
	for(int i=0;i<2*n;i++){
		cout<<v[i]<<" ";
	}	
	cout<<endl;
  }
  return 0;
}