private com.google.protobuf.SingleFieldBuilderV3<
            com.google.protobuf.Duration,
            com.google.protobuf.Duration.Builder,
            com.google.protobuf.DurationOrBuilder>
        getIntervalFieldBuilder() {
      if (intervalBuilder_ == null) {
        intervalBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.protobuf.Duration,
                com.google.protobuf.Duration.Builder,
                com.google.protobuf.DurationOrBuilder>(
                getInterval(), getParentForChildren(), isClean());
        interval_ = null;
      }
      return intervalBuilder_;
    }
<pre>
Create sprites at regular intervals. Valid range is [1 second, 1 hour] and
the default value is `10s`.
</pre>

<code>.google.protobuf.Duration interval = 7;</code>
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/SpriteSheet.java