private com.google.protobuf.SingleFieldBuilderV3<
              com.google.protobuf.Timestamp,
              com.google.protobuf.Timestamp.Builder,
              com.google.protobuf.TimestampOrBuilder>
          getStartTimeFieldBuilder() {
        if (startTimeBuilder_ == null) {
          startTimeBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.protobuf.Timestamp,
                  com.google.protobuf.Timestamp.Builder,
                  com.google.protobuf.TimestampOrBuilder>(
                  getStartTime(), getParentForChildren(), isClean());
          startTime_ = null;
        }
        return startTimeBuilder_;
      }
<pre>
Start timestamp of this track.
</pre>

<code>.google.protobuf.Timestamp start_time = 2;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/OccupancyCountingPredictionResult.java