#include<bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define lowbit(x) (x&-x)
#define log(x) (31^__builtin_clz(x))
using namespace std;
const int p=1e9+7;
int l[1000005],r[1000005];
int s[1000005];
inline int calc(int x,int y){
	int tmp=x^y;
	for(int i=20;i>=0;i--){
		if(tmp>>i&1)return 20-i;
	}
	return 21;
}
void solve(){
	int m,n;
	cin>>m>>n;
	for(int i=1;i<=n;i++){
		cin>>l[i]>>r[i];
	}
	for(int i=0;i<(1<<m);i++)s[i]=0;
	for(int i=l[1];i<=r[1];i++){
		s[i]=i+s[i-1];
		if(s[i]>=p)s[i]-=p;
	}
	for(int i=2;i<=n;i++){
		int now=l[i]-1;
		for(int j=l[i];j<=r[i];j++){
			while(now>l[i-1]&&calc(now-1,l[i])<=calc(i,l[i])&&calc(now-1,r[i-1])>=calc(i,r[i-1]))now--;
			s[j]=s[r[i-1]];
			if(now>0)s[j]-=s[now];
			if(s[j]<0)s[j]+=p;
		}
		s[l[i]]=1ll*s[l[i]]*l[i]%p;
		for(int j=l[i]+1;j<=r[i];j++){
			s[j]=(1ll*s[j]*j+s[j-1])%p;
		}
	}
	// for(int i=0;i<(1<<m);i++)cout<<s[i]<<"\n";
	cout<<s[(1<<m)-1]<<"\n";
}
int main(){
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int t=1;
	cin>>t;
	while(t--)solve();
	return 0;
}