#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>

#define ll long long
#define inf 1000000010
#define eps 1e-10
#define md 1000000007
#define N 200010
using namespace std;
struct data { int pos,ty;} q[N];
ll mi[N],p[N];
int a[N];
bool cmp(data a,data b) { return a.pos<b.pos;}
void ycl()
{
    memset(a,0,sizeof(a));
}
int main()
{
    mi[0]=1; for (int i=1;i<=100010;i++) mi[i]=mi[i-1]*2%md;
    int tt;
    scanf("%d",&tt);
    while (tt--)
    {
        ycl();
        int n;
        scanf("%d",&n);
        int w=0;
        for (int i=1;i<=n;i++)
        {
            w++; scanf("%d",&q[w].pos); q[w].ty=1;
            w++; scanf("%d",&q[w].pos); q[w].ty=-1;
        }
        sort(q+1,q+w+1,cmp);
        q[0].pos=-inf; int tot=0;
        for (int i=1;i<=w;i++)
        {
            if (q[i].pos!=q[i-1].pos) { tot++; p[tot]=q[i].pos;}
            a[tot]+=q[i].ty;
        }
        for (int i=1;i<=tot;i++) a[i]+=a[i-1];
        //for (int i=1;i<=tot;i++) printf("%d %d\n",p[i],a[i]);
        ll ans=0;
        for (int i=1;i<tot;i++) ans=(ans+(mi[a[i]]-1+md)*mi[n-a[i]]%md*(p[i+1]-p[i]))%md;
        printf("%I64d\n",ans);
    }
    return 0;
}