title: Change Firestore QuerySnaphot Size in realtime
body: <p>Is there any way to conditionally change the <code>querySnapshot.size</code> to 0 in runtime so that the <code>forEach()</code> runs only specified number of time ? And would doing it be a good practice ?</p>
  <pre class="lang-js prettyprint-override"><code>db.collection(&quot;cities&quot;).get().then((querySnapshot) =&gt; {
      let count = 0;
      querySnapshot.forEach((doc) =&gt; {
          if(count === 5) {
              //change querySnapshot.size
          }
          console.log(doc.id, &quot; =&gt; &quot;, doc.data());
          count++;
      });
  });
  </code></pre>