private com.google.protobuf.SingleFieldBuilderV3<
            com.google.protobuf.Timestamp,
            com.google.protobuf.Timestamp.Builder,
            com.google.protobuf.TimestampOrBuilder>
        getSegmentStartTimeFieldBuilder() {
      if (segmentStartTimeBuilder_ == null) {
        segmentStartTimeBuilder_ =
            new com.google.protobuf.SingleFieldBuilderV3<
                com.google.protobuf.Timestamp,
                com.google.protobuf.Timestamp.Builder,
                com.google.protobuf.TimestampOrBuilder>(
                getSegmentStartTime(), getParentForChildren(), isClean());
        segmentStartTime_ = null;
      }
      return segmentStartTimeBuilder_;
    }
<pre>
The beginning, inclusive, of the video's time segment in which the
current identifications happens.
</pre>

<code>.google.protobuf.Timestamp segment_start_time = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/VideoObjectTrackingPredictionResult.java