title: How to count documents returned by Node-MongoDB-native stream()?
body: <p>When I <a href="http://mongodb.github.io/node-mongodb-native/api-generated/cursor.html#stream" rel="nofollow">stream()</a> documents in the <a href="http://mongodb.github.io/node-mongodb-native/" rel="nofollow">NodeJS MongoDB native driver</a>, how do I determine the total number of documents that will be returned? Useful for reporting query progress, for example.</p>
  
  <pre><code>var stream = collection.find(query, fields, options).stream()
      .on("data", onData)
      .on("end", onEnd)
      .on("error", onError);
  </code></pre>