#include<cstdio>

#include<algorithm>

#include<vector>

#include<queue>

#include<iostream>

#include<cstring>

using namespace std;

const int maxn=600;

const int INF=1000000;

# define  pb push_back

int A[maxn],mapp[INF],bass[INF];

int s,t;

struct Edge{

	int from,to,cap;

	Edge(int u,int v,int c):from(u),to(v),cap(c) {}

};

 vector<Edge>edges;

 struct Dicnic{

   vector<int>G[maxn];

   int d[maxn],vis[maxn],cur[maxn];

   queue<int>Q;

   void init(){

   	for(int i=0;i<maxn;++i)G[i].clear();

   	edges.clear();

   }

   void addedge(int u,int v,int c,int cnt){

   	edges.pb(Edge(u,v,c));               //正向弧

   	edges.pb(Edge(v,u,0));               //反向弧

   	int m=edges.size();

   	G[u].pb(m-2);

   	G[v].pb(m-1);

   	if(cnt>0)mapp[cnt]=m-1;

   }

   int BFS()

   {

    memset(vis,0,sizeof(vis));

    d[s]=0,vis[s]=1;Q.push(s);

    while(!Q.empty()){

    	int u=Q.front();Q.pop();

    	int sz=G[u].size();

    	for(int i=0;i<sz;++i){

    		Edge e=edges[G[u][i]];

    		if(!vis[e.to]&&e.cap>0){

    			d[e.to]=d[u]+1,vis[e.to]=1;

    			Q.push(e.to);

    		}

    	}

    }

    return vis[t];

   }

   int dfs(int x,int a){

       if(x==t)return a;

       int sz=G[x].size();

       int f,flow=0;

       for(int i=cur[x];i<sz;++i){

       	Edge e=edges[G[x][i]];

            cur[x]=i;

       	if(d[e.to]==d[x]+1&&e.cap>0){

       		f=dfs(e.to,min(a,e.cap));

       		if(f)

       		{

       			int u=G[x][i];

       			a-=f;

                edges[u].cap-=f;

                edges[u^1].cap+=f;

                flow+=f;

                if(a==0)break;

       		}

       	}

       }

       return flow;

   }

   int maxflow(){

   	int ans=0;

   	while(BFS()){

      memset(cur,0,sizeof(cur));

      ans+=dfs(s,INF);

   	}

   	return ans;

   }

}op;

int main(){

     int T;cin>>T;

     s=0,t=420;

    for(int cas=1;cas<=T;++cas){

    	memset(A,0,sizeof(A));

    	op.init();

	int n,m,sum=0;

	cin>>n>>m;

	for(int i=1;i<=m;++i){

		int a,b,c,d;

		cin>>a>>b>>c>>d;

		bass[i]=c;

		op.addedge(a,b,d-c,i);

		A[a]-=c,A[b]+=c;

	}

            for(int i=1;i<=m;++i){

            	             if(A[i]>0){op.addedge(s,i,A[i],0);sum+=A[i];}

            	             if(A[i]<0)op.addedge(i,t,-A[i],0);

            }

            int  flow=op.maxflow();

            if(flow==sum){

            	      cout<<"YES"<<endl;

            	      for(int i=1;i<m;++i)cout<<edges[mapp[i]].cap+bass[i]<<endl;

            	      cout<<edges[mapp[m]].cap+bass[m];

            	     if(cas!=T)cout<<endl;

            }else cout<<"NO"<<endl;

            if(cas!=T)cout<<endl;

      }

      return 0;

}