public Builder clearDuration() {
        bitField0_ = (bitField0_ & ~0x00000001);
        duration_ = null;
        if (durationBuilder_ != null) {
          durationBuilder_.dispose();
          durationBuilder_ = null;
        }
        onChanged();
        return this;
      }
<pre>
Duration of an ad opportunity. Must be greater than 0.
</pre>

<code>.google.protobuf.Duration duration = 1;</code>
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/Event.java