@java.lang.Override
    public int getSerializedSize() {
      int size = memoizedSize;
      if (size != -1) return size;

      size = 0;
      if (boxId_ != 0L) {
        size += com.google.protobuf.CodedOutputStream.computeInt64Size(1, boxId_);
      }
      if (((bitField0_ & 0x00000001) != 0)) {
        size +=
            com.google.protobuf.CodedOutputStream.computeMessageSize(2, getNormalizedBoundingBox());
      }
      if (java.lang.Float.floatToRawIntBits(score_) != 0) {
        size += com.google.protobuf.CodedOutputStream.computeFloatSize(3, score_);
      }
      if (((bitField0_ & 0x00000002) != 0)) {
        size += com.google.protobuf.CodedOutputStream.computeMessageSize(4, getEntity());
      }
      if (trackId_ != 0L) {
        size += com.google.protobuf.CodedOutputStream.computeInt64Size(5, trackId_);
      }
      size += getUnknownFields().getSerializedSize();
      memoizedSize = size;
      return size;
    }
<pre>
An unique id to identify a track. It should be consistent across frames.
It only exists if tracking is enabled.
</pre>

<code>int64 track_id = 5;</code>

@return The trackId.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/OccupancyCountingPredictionResult.java