public Builder mergeSegmentStartTime(com.google.protobuf.Timestamp value) {
      if (segmentStartTimeBuilder_ == null) {
        if (((bitField0_ & 0x00000001) != 0)
            && segmentStartTime_ != null
            && segmentStartTime_ != com.google.protobuf.Timestamp.getDefaultInstance()) {
          getSegmentStartTimeBuilder().mergeFrom(value);
        } else {
          segmentStartTime_ = value;
        }
      } else {
        segmentStartTimeBuilder_.mergeFrom(value);
      }
      if (segmentStartTime_ != null) {
        bitField0_ |= 0x00000001;
        onChanged();
      }
      return this;
    }
<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