//未提交
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int maxn=1000,maxm=100000,inf=0x3f3f3f3f;
struct edge{int from,v,flow;}e[maxm];
int S,T,TT,n,m,tot=1,first[maxn],cur[maxn],in[maxn],d[maxn],q[1010],lows[maxm];
void insert(int u,int v,int w)
{tot++;e[tot].v=v;e[tot].flow=w;e[tot].from=first[u];first[u]=tot;tot++;e[tot].v=u;e[tot].flow=0;e[tot].from=first[v];first[v]=tot;
}
bool bfs()
{memset(d,-1,sizeof(d));int head=0,tail=1;q[0]=S;d[S]=0;while(head!=tail){int x=q[head++];if(head>1000)head=0;for(int i=first[x];i;i=e[i].from)if(d[e[i].v]==-1&&e[i].flow){d[e[i].v]=d[x]+1;q[tail++]=e[i].v;if(tail>1000)tail=0;}}return d[T]!=-1;
}
int dfs(int x,int a)
{if(x==T||a==0)return a;int flow=0,f;for(int& i=cur[x];i;i=e[i].from)if(d[e[i].v]==d[x]+1&&(f=dfs(e[i].v,min(a,e[i].flow)))>0){e[i].flow-=f;e[i^1].flow+=f;a-=f;flow+=f;if(a==0)break;}return flow;
}
int main()
{scanf("%d",&TT);while(TT--){memset(first,0,sizeof(first));memset(in,0,sizeof(in));tot=1;scanf("%d%d",&n,&m);for(int i=1;i<=m;i++){int u,v,w;scanf("%d%d%d%d",&u,&v,&lows[i],&w);in[u]-=lows[i];in[v]+=lows[i];insert(u,v,w-lows[i]);}S=0,T=n+1;for(int i=1;i<=n;i++){if(in[i]>0)insert(S,i,in[i]);if(in[i]<0)insert(i,T,-in[i]);}while(bfs()){for(int i=0;i<=n+1;i++)cur[i]=first[i];dfs(S,inf);}bool ok=1;for(int i=first[S];i;i=e[i].from)if(e[i].flow)ok=0;if(ok){printf("YES\n");for(int i=2;i<=m*2;i+=2)printf("%d\n",e[i^1].flow+lows[i>>1]);}else printf("NO\n");}return 0;
}