public int getElementaryStreamsCount() {
    return elementaryStreams_.size();
  }
<pre>
List of `ElementaryStream.key`s multiplexed in this stream.
</pre>

<code>repeated string elementary_streams = 4;</code>

@return The count of elementaryStreams.
java-video-transcoder/proto-google-cloud-video-transcoder-v1/src/main/java/com/google/cloud/video/transcoder/v1/MuxStream.java